refactor(zellij): improve session/layout handling

Adds Reinstall method to PackageManager and AURHelper interfaces
so modules can invoke the concrete Reinstall helpers behind the
interface. *Pacman and *Yay already satisfy it.

.gitea/workflows/ci.yml

@@ -0,0 +1,52 @@
+name: ci
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: archlinux:latest
+    steps:
+      - name: Install container prereqs
+        run: pacman -Sy --needed --noconfirm base-devel git shellcheck
+
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: go vet
+        run: go vet ./...
+
+      - name: gofmt check
+        run: |
+          diff=$(gofmt -l .)
+          if [ -n "$diff" ]; then
+            echo "files need gofmt:"
+            echo "$diff"
+            exit 1
+          fi
+
+      - name: go build
+        run: go build ./...
+
+      - name: go test -race
+        run: go test -race ./...
+
+      - name: shellcheck bootstrap.sh
+        run: shellcheck bootstrap.sh
+
+      - name: Install goreleaser
+        run: go install github.com/goreleaser/goreleaser/v2@latest
+
+      - name: goreleaser check
+        run: $(go env GOPATH)/bin/goreleaser check

.gitea/workflows/release.yml

@@ -0,0 +1,30 @@
+name: release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Run goreleaser
+        uses: goreleaser/goreleaser-action@v6
+        with:
+          distribution: goreleaser
+          version: '~> v2'
+          args: release --clean
+        env:
+          GITEA_TOKEN: ${{ secrets.RELEASE_TOKEN }}

.gitignore

@@ -1 +1,16 @@
-.idea
+.idea
+WokwiKey.txt
+
+# Go
+/archduino
+/dist/
+*.test
+*.out
+coverage.*
+.worktrees/
+
+# goreleaser output
+dist/
+
+# generated shell completions
+completions/

.goreleaser.yaml

@@ -0,0 +1,76 @@
+version: 2
+
+project_name: archduino
+
+before:
+  hooks:
+    - mkdir -p completions
+    - sh -c "go run ./cmd/archduino completion bash > completions/archduino.bash"
+    - sh -c "go run ./cmd/archduino completion zsh  > completions/_archduino"
+    - sh -c "go run ./cmd/archduino completion fish > completions/archduino.fish"
+
+builds:
+  - id: archduino
+    main: ./cmd/archduino
+    binary: archduino
+    env:
+      - CGO_ENABLED=0
+    goos:
+      - linux
+    goarch:
+      - amd64
+      - arm64
+    ldflags:
+      - -s -w
+      - -X main.version={{ .Version }}
+      - -X main.commit={{ .Commit }}
+      - -X main.date={{ .Date }}
+
+archives:
+  - id: default
+    name_template: "archduino_{{ .Version }}_linux_{{ .Arch }}"
+    formats: [tar.gz]
+    files:
+      - README.md
+      - LICENSE
+      - src: completions/archduino.bash
+        dst: completions/archduino.bash
+      - src: completions/_archduino
+        dst: completions/_archduino
+      - src: completions/archduino.fish
+        dst: completions/archduino.fish
+
+checksum:
+  name_template: "checksums.txt"
+  algorithm: sha256
+
+changelog:
+  use: git
+  sort: asc
+  filters:
+    exclude:
+      - '^chore:'
+      - '^docs:'
+      - '^test:'
+      - '^ci:'
+      - '^style:'
+      - '^refactor:'
+      - 'Merge pull request'
+      - 'Merge branch'
+  groups:
+    - title: Features
+      regexp: '^feat(\(.*\))?:'
+      order: 0
+    - title: Bug fixes
+      regexp: '^(fix|perf)(\(.*\))?:'
+      order: 1
+    - title: Others
+      order: 999
+
+gitea_urls:
+  api: https://gitlab.hive-brain.de/api/v1
+  download: https://gitlab.hive-brain.de
+
+release:
+  draft: false
+  prerelease: auto

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 MDietermann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,39 @@
+.PHONY: build snapshot release completions clean help
+
+GO ?= go
+BIN := archduino
+
+help: ## Show this help
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "  %-14s %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+
+build: ## Local dev build into ./archduino
+	$(GO) build -o $(BIN) ./cmd/archduino
+
+completions: ## Regenerate shell completions into completions/
+	@mkdir -p completions
+	$(GO) run ./cmd/archduino completion bash > completions/archduino.bash
+	$(GO) run ./cmd/archduino completion zsh  > completions/_archduino
+	$(GO) run ./cmd/archduino completion fish > completions/archduino.fish
+
+snapshot: ## Local goreleaser dry run into dist/
+	goreleaser release --snapshot --clean
+
+clean: ## Remove build artifacts
+	rm -rf dist/ completions/ $(BIN)
+
+release: ## Compute next SemVer from commits, tag, and push
+	@command -v svu >/dev/null || { echo "svu not found. Run: go install github.com/caarlos0/svu@latest"; exit 1; }
+	@test -z "$$(git status --porcelain)" || { echo "working tree is dirty; commit or stash first"; exit 1; }
+	@branch=$$(git rev-parse --abbrev-ref HEAD); \
+	 if [ "$$branch" != "master" ]; then echo "must be on master (currently on $$branch)"; exit 1; fi
+	@current=$$(svu current 2>/dev/null || echo "none"); \
+	 next=$$(svu next); \
+	 echo "Current: $$current"; \
+	 echo "Next:    $$next"; \
+	 echo; \
+	 echo "Commits since $$current:"; \
+	 if [ "$$current" = "none" ]; then git log --oneline; else git log --oneline $$current..HEAD; fi; \
+	 echo; \
+	 printf "Tag %s and push? [y/N] " "$$next"; read ans; \
+	 if [ "$$ans" != "y" ] && [ "$$ans" != "Y" ]; then echo "aborted"; exit 1; fi; \
+	 git tag "$$next" && git push origin "$$next"

README.md

@@ -73,22 +73,35 @@ This updates Starship, Zellij, Lazygit, Yazi, and NvChad in one step.
 
 ## 🚀 Quickstart
 
+## Installation
+
+One-line install on Arch Linux:
+
 ```bash
-git clone --depth=1 https://github.com/<your-username>/ArduinoArch.git
-cd ArduinoArch
-chmod +x install.sh
-./install.sh
+curl -fsSL https://gitlab.hive-brain.de/MDietermann/Archduino/raw/branch/master/bootstrap.sh | bash
 ```
 
-The installer will:
+This fetches the latest release, verifies its checksum, installs `archduino`
+to `/usr/local/bin`, installs shell completions, and launches
+`archduino install`.
 
-1. Show a banner with detected OS and package manager
-2. Let you pick your **colorscheme** (applied to all tools)
-3. Let you choose between **progress bar** or **verbose** output
-4. Ask for your sudo password **once** (cached for the entire install)
-5. Run through all 11 setup steps automatically
+### Development
 
-After it finishes, start a new shell or run `source ~/.zshrc`.
+Local build:
+
+```bash
+make build
+./archduino --help
+```
+
+Releasing (maintainers only):
+
+```bash
+go install github.com/caarlos0/svu@latest
+make release   # prompts with computed next version, tags, pushes
+```
+
+After install, start a new shell or run `source ~/.zshrc`.
 
 ---
 
@@ -96,7 +109,10 @@ After it finishes, start a new shell or run `source ~/.zshrc`.
 
 ```
 ArduinoArch/
-├── install.sh              # Main entry point
+├── bootstrap.sh            # Curl-piped installer shim (fetches latest release)
+├── cmd/archduino/          # Go CLI entry point
+├── internal/               # Go packages (install steps, theming, detect, etc.)
+├── install.sh.legacy       # Deprecated legacy Bash installer (kept for reference)
 └── lib/
     ├── common.sh           # Colors, helpers, environment detection, progress bar
     ├── themes.sh           # Colorscheme selection menu

bootstrap.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+REPO="MDietermann/Archduino"
+BASE_URL="${ARCHDUINO_RELEASE_BASE:-https://gitlab.hive-brain.de}"
+API_URL="${BASE_URL}/api/v1"
+
+err() { echo "bootstrap: error: $*" >&2; exit 1; }
+msg() { echo "==> $*"; }
+
+# Arch gate
+[ -f /etc/arch-release ] || err "Archduino v1 supports Arch Linux only."
+
+# Arch detect
+case "$(uname -m)" in
+  x86_64)  ARCH="amd64" ;;
+  aarch64) ARCH="arm64" ;;
+  *)       err "unsupported architecture: $(uname -m)" ;;
+esac
+
+# Prereqs
+msg "Installing prerequisites (sudo, git, curl, ca-certificates)"
+sudo pacman -Sy --needed --noconfirm sudo git curl ca-certificates
+
+# Discover latest release
+msg "Querying latest release from Gitea"
+API_ENDPOINT="${API_URL}/repos/${REPO}/releases/latest"
+RELEASE_JSON=$(curl -fsSL "$API_ENDPOINT") || err "failed to fetch ${API_ENDPOINT}"
+
+# Extract tag_name without requiring jq
+TAG=$(printf '%s' "$RELEASE_JSON" | grep -o '"tag_name":[[:space:]]*"[^"]*"' | head -1 | sed 's/.*"\([^"]*\)"$/\1/')
+[ -n "$TAG" ] || err "could not parse tag_name from release metadata"
+VERSION="${TAG#v}"
+msg "Latest release: ${TAG}"
+
+# Download
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+TARBALL="archduino_${VERSION}_linux_${ARCH}.tar.gz"
+CHECKSUMS="checksums.txt"
+DL_BASE="${BASE_URL}/${REPO}/releases/download/${TAG}"
+
+msg "Downloading ${TARBALL}"
+curl -fsSL -o "${TMP}/${TARBALL}"  "${DL_BASE}/${TARBALL}"  || err "tarball download failed"
+curl -fsSL -o "${TMP}/${CHECKSUMS}" "${DL_BASE}/${CHECKSUMS}" || err "checksums download failed"
+
+# Verify
+msg "Verifying checksum"
+(cd "$TMP" && sha256sum --check --ignore-missing "$CHECKSUMS") || err "checksum verification failed"
+
+# Extract
+msg "Extracting"
+tar -xzf "${TMP}/${TARBALL}" -C "$TMP"
+
+# Install
+msg "Installing to /usr/local/bin (sudo)"
+sudo install -m 0755 "${TMP}/archduino" /usr/local/bin/archduino
+
+msg "Installing shell completions"
+sudo install -Dm 0644 "${TMP}/completions/archduino.bash" /usr/share/bash-completion/completions/archduino
+sudo install -Dm 0644 "${TMP}/completions/_archduino"     /usr/share/zsh/site-functions/_archduino
+sudo install -Dm 0644 "${TMP}/completions/archduino.fish" /usr/share/fish/vendor_completions.d/archduino.fish
+
+msg "Launching: archduino install $*"
+exec /usr/local/bin/archduino install "$@"

cmd/archduino/main.go

@@ -0,0 +1,443 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/charmbracelet/huh"
+	"github.com/spf13/cobra"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/engine"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/arduinocli"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/fonts"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/gittools"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/neovim"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/packages"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/renode"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/shellconfig"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/starship"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/themes"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/yazi"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/zellij"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/modules/zsh"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/privilege"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/state"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/subcommands/doctor"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/subcommands/newproject"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/theming"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/tui"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/tui/dashboard"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/tui/wizard"
+)
+
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
+)
+
+// buildRegistry constructs a module registry populated with all Plan 3a
+// modules, wired against the provided config and platform dependencies.
+// It replaces the earlier init()-time hello-module registration now that
+// the real modules need runtime config to be instantiated.
+func buildRegistry(cfg config.Config, themeID string) (*module.Registry, error) {
+	reg := module.NewRegistry()
+	runner := platform.ExecRunner{}
+	pm := platform.NewPacman(runner)
+	yay := platform.NewYay(runner)
+	git := platform.GitClient{Runner: runner}
+
+	mods := []module.Module{
+		packages.New(cfg.Packages.Base, pm),
+		gittools.New([]string{"lazygit"}, pm),
+		starship.New([]string{"starship"}, pm),
+		yazi.New([]string{"yazi"}, pm),
+		zsh.New(cfg.Zsh, pm, git),
+		fonts.New(cfg.Fonts, pm, yay),
+		zellij.New(cfg.Zellij, pm),
+		themes.New(cfg.Themes),
+		arduinocli.New(cfg.ArduinoCLI, runner),
+		shellconfig.New(cfg.ShellConfig),
+		neovim.New(cfg.Neovim, themeID, pm, git),
+		renode.New(cfg.Renode, pm, yay),
+	}
+	for _, m := range mods {
+		if err := reg.Register(m); err != nil {
+			return nil, err
+		}
+	}
+	return reg, nil
+}
+
+func main() {
+	root := &cobra.Command{
+		Use:           "archduino",
+		Short:         "Archduino installer and toolbox",
+		SilenceUsage:  true,
+		SilenceErrors: true,
+		Version:       version,
+	}
+	root.AddCommand(newInstallCmd())
+	root.AddCommand(newThemeCmd())
+	root.AddCommand(newNewCmd())
+	root.AddCommand(newDoctorCmd())
+	root.AddCommand(newVersionCmd())
+
+	// Wire SIGINT/SIGTERM to a cancellable context so long-running phases
+	// (engine.Run, sudo keepalive) observe the cancellation promptly.
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	if err := root.ExecuteContext(ctx); err != nil {
+		fmt.Fprintln(os.Stderr, "error:", err)
+		os.Exit(1)
+	}
+}
+
+func newInstallCmd() *cobra.Command {
+	var (
+		noTUI       bool
+		dryRun      bool
+		halt        bool
+		noSudo      bool
+		force       bool
+		only        []string
+		skip        []string
+		overlayPath string
+	)
+	cmd := &cobra.Command{
+		Use:   "install",
+		Short: "Install or reconcile the Archduino toolset",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx := cmd.Context()
+			if ctx == nil {
+				ctx = context.Background()
+			}
+
+			// Gate: v1 supports Arch only. Non-Arch hosts would silently run
+			// the hello module today but fail on Plan 3's pacman-dependent
+			// modules — fail fast with a clear message instead.
+			if !noSudo { // --no-sudo implies a test/container context; skip the gate
+				p, derr := platform.Detect()
+				if derr != nil {
+					return fmt.Errorf("platform detect: %w", derr)
+				}
+				if p.Distro != platform.DistroArch {
+					return fmt.Errorf("archduino requires Arch Linux (detected distro: %s)", p.Distro)
+				}
+			}
+
+			cfg, err := config.Load(overlayPath)
+			if err != nil {
+				return err
+			}
+
+			reg, err := buildRegistry(cfg, "")
+			if err != nil {
+				return fmt.Errorf("build registry: %w", err)
+			}
+
+			selected, err := resolveSelection(reg, cfg, only, skip)
+			if err != nil {
+				return err
+			}
+
+			// Acquire sudo unless dry-run or explicitly skipped.
+			if !dryRun && !noSudo {
+				k, err := privilege.Acquire(ctx, privilege.ExecSudo{}, 50*time.Second)
+				if err != nil {
+					return err
+				}
+				defer k.Stop()
+			}
+
+			started := time.Now().UTC()
+			var (
+				sum           engine.Summary
+				runErr        error
+				selectedTheme = cfg.ThemeOverrides["__active"]
+			)
+
+			if noTUI || dryRun {
+				// Plain-output path: preserve the Plan 1 behaviour. Dry-run
+				// always uses plain output because the dashboard has nothing
+				// to animate when no Apply happens.
+				reporter := engine.NewPlainReporter(os.Stdout)
+				sum, runErr = engine.Run(ctx, reg, engine.RunOptions{
+					Selected:    selected,
+					DryRun:      dryRun,
+					HaltOnError: halt,
+					Force:       force,
+					Reporter:    reporter,
+				})
+			} else {
+				// TUI path: wizard → dashboard. If the user does not confirm,
+				// we exit cleanly with a zero-summary and no error.
+				initial := tui.NewWizardState(cfg, reg)
+				initial.Force = force
+				// Pre-filter the wizard's module list by --only/--skip so the
+				// user cannot accidentally widen selection in the TUI beyond
+				// what they asked for on the CLI.
+				if len(selected) < len(initial.Modules) {
+					wanted := map[string]bool{}
+					for _, id := range selected {
+						wanted[id] = true
+					}
+					for i := range initial.Modules {
+						initial.Modules[i].Selected = wanted[initial.Modules[i].ID]
+					}
+				}
+
+				finalState, confirmed, werr := wizard.Run(ctx, reg, initial)
+				if werr != nil {
+					return werr
+				}
+				if !confirmed {
+					fmt.Fprintln(os.Stdout, "installation cancelled")
+					return nil
+				}
+				// Rebuild the registry with the theme the user chose in the
+				// wizard so theme-aware modules (e.g. neovim in Task 7) pick
+				// up the selection instead of the empty pre-wizard default.
+				reg, err = buildRegistry(cfg, finalState.ThemeID)
+				if err != nil {
+					return fmt.Errorf("build registry: %w", err)
+				}
+				if finalState.ThemeID != "" {
+					selectedTheme = finalState.ThemeID
+				}
+				// Either the CLI flag or the wizard toggle can force halt-on-error.
+				sum, runErr = dashboard.Run(ctx, reg, finalState, halt || finalState.HaltOnError)
+			}
+
+			ended := time.Now().UTC()
+			if runErr != nil {
+				return runErr
+			}
+
+			// Apply the wizard-selected theme (no-op if user chose a theme
+			// whose configs are already on disk). Skipped on dry-run.
+			if !dryRun && selectedTheme != "" {
+				if err := theming.Apply(cfg, selectedTheme); err != nil {
+					fmt.Fprintf(os.Stderr, "warning: theme apply failed: %v\n", err)
+				}
+			}
+
+			ok, fail, skipped := sum.Counts()
+			fmt.Fprintf(os.Stdout, "\nsummary: %d succeeded, %d failed, %d skipped\n", ok, fail, skipped)
+			for _, r := range sum.Results {
+				line := fmt.Sprintf("  %-16s %s", r.ID, r.Status)
+				if r.Err != nil {
+					line += "  — " + r.Err.Error()
+				}
+				fmt.Fprintln(os.Stdout, line)
+			}
+
+			if !dryRun {
+				if err := writeState(started, ended, sum); err != nil {
+					fmt.Fprintln(os.Stderr, "warning: state write failed:", err)
+				}
+			}
+
+			if fail > 0 {
+				return fmt.Errorf("%d module(s) failed", fail)
+			}
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&noTUI, "no-tui", false, "plain-text output, no interactive UI")
+	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show planned actions without applying")
+	cmd.Flags().BoolVar(&halt, "halt-on-error", false, "stop at first failure instead of continuing siblings")
+	cmd.Flags().BoolVar(&noSudo, "no-sudo", false, "skip upfront sudo -v (for tests / containers with passwordless sudo)")
+	cmd.Flags().BoolVar(&force, "force", false, "reapply every selected module, ignoring current state")
+	cmd.Flags().StringSliceVar(&only, "only", nil, "comma-separated module IDs to run (exclusive with --skip)")
+	cmd.Flags().StringSliceVar(&skip, "skip", nil, "comma-separated module IDs to skip")
+	cmd.Flags().StringVar(&overlayPath, "config", "", "path to overlay.yaml (default: ~/.config/archduino/overlay.yaml)")
+	cmd.MarkFlagsMutuallyExclusive("only", "skip")
+	return cmd
+}
+
+func resolveSelection(reg *module.Registry, cfg config.Config, only, skip []string) ([]string, error) {
+	all := reg.All()
+	known := map[string]bool{}
+	for _, m := range all {
+		known[m.Meta().ID] = true
+	}
+
+	// Validate every explicit ID the user passed so a typo in --only does not
+	// silently fall through to "run all modules".
+	for _, id := range only {
+		if !known[id] {
+			return nil, fmt.Errorf("unknown module in --only: %q", id)
+		}
+	}
+	for _, id := range skip {
+		if !known[id] {
+			return nil, fmt.Errorf("unknown module in --skip: %q", id)
+		}
+	}
+
+	disabled := map[string]bool{}
+	for _, d := range cfg.DisabledModules {
+		disabled[d] = true
+	}
+	for _, d := range skip {
+		disabled[d] = true
+	}
+	onlySet := map[string]bool{}
+	for _, o := range only {
+		onlySet[o] = true
+	}
+	var out []string
+	for _, m := range all {
+		id := m.Meta().ID
+		if disabled[id] {
+			continue
+		}
+		if len(onlySet) > 0 && !onlySet[id] {
+			continue
+		}
+		out = append(out, id)
+	}
+	return out, nil
+}
+
+func writeState(started, ended time.Time, sum engine.Summary) error {
+	s, err := state.DefaultStore()
+	if err != nil {
+		return err
+	}
+	rec := state.RunRecord{StartedAt: started, EndedAt: ended}
+	for _, r := range sum.Results {
+		mr := state.ModuleRecord{ID: r.ID, Status: string(r.Status), At: ended}
+		if r.Err != nil {
+			mr.Error = r.Err.Error()
+		}
+		rec.Modules = append(rec.Modules, mr)
+	}
+	return s.Save(rec, 10)
+}
+
+func newThemeCmd() *cobra.Command {
+	var overlayPath string
+	cmd := &cobra.Command{
+		Use:   "theme [id]",
+		Short: "Switch the active colorscheme across tools",
+		Args:  cobra.MaximumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cfg, err := config.Load(overlayPath)
+			if err != nil {
+				return err
+			}
+
+			// "list" short-circuit.
+			if len(args) == 1 && args[0] == "list" {
+				for _, t := range theming.List() {
+					fmt.Printf("%s — %s\n", t.ID, t.DisplayName)
+				}
+				return nil
+			}
+
+			var id string
+			if len(args) == 1 {
+				id = args[0]
+			} else {
+				themes := theming.List()
+				opts := make([]huh.Option[string], 0, len(themes))
+				for _, t := range themes {
+					opts = append(opts, huh.NewOption(t.DisplayName, t.ID))
+				}
+				id = cfg.ThemeOverrides["__active"]
+				if id == "" && len(themes) > 0 {
+					id = themes[0].ID
+				}
+				form := huh.NewForm(huh.NewGroup(
+					huh.NewSelect[string]().Title("Choose a theme").Options(opts...).Value(&id),
+				))
+				if err := form.RunWithContext(cmd.Context()); err != nil {
+					if errors.Is(err, huh.ErrUserAborted) {
+						return nil
+					}
+					return err
+				}
+			}
+
+			if err := theming.Apply(cfg, id); err != nil {
+				return err
+			}
+			fmt.Printf("Applied theme: %s\n", id)
+			fmt.Println("Restart zellij and neovim to see the new colors.")
+			return nil
+		},
+	}
+	cmd.Flags().StringVar(&overlayPath, "overlay", "", "path to overlay.yaml (defaults to ~/.config/archduino/overlay.yaml)")
+	return cmd
+}
+
+func newNewCmd() *cobra.Command {
+	var overlayPath string
+	cmd := &cobra.Command{
+		Use:   "new <project> <board>",
+		Short: "Scaffold a new Arduino sketch directory",
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cfg, err := config.Load(overlayPath)
+			if err != nil {
+				return err
+			}
+			project, board := args[0], args[1]
+			if err := newproject.Run(cfg, project, board); err != nil {
+				return err
+			}
+			fmt.Printf("Created %s/ (board: %s)\n", project, board)
+			fmt.Printf("Next: cd %s && nvim %s.ino\n", project, project)
+			return nil
+		},
+	}
+	cmd.Flags().StringVar(&overlayPath, "overlay", "", "path to overlay.yaml")
+	return cmd
+}
+
+func newDoctorCmd() *cobra.Command {
+	var overlayPath string
+	cmd := &cobra.Command{
+		Use:   "doctor",
+		Short: "Report module convergence and pinned-tool version drift",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cfg, err := config.Load(overlayPath)
+			if err != nil {
+				return err
+			}
+			reg, err := buildRegistry(cfg, cfg.ThemeOverrides["__active"])
+			if err != nil {
+				return fmt.Errorf("build registry: %w", err)
+			}
+			code := doctor.Run(cmd.Context(), cfg, reg, platform.ExecRunner{}, os.Stdout)
+			if code != 0 {
+				os.Exit(code)
+			}
+			return nil
+		},
+	}
+	cmd.Flags().StringVar(&overlayPath, "overlay", "", "path to overlay.yaml")
+	return cmd
+}
+
+func newVersionCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "version",
+		Short: "Print version, commit, and build date",
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Printf("archduino %s\ncommit: %s\ndate:   %s\n", version, commit, date)
+		},
+	}
+}

docs/superpowers/plans/2026-04-14-ci-workflow.md

@@ -0,0 +1,205 @@
+# CI Workflow Implementation Plan (Plan 4d)
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add a single Gitea Actions CI workflow that runs `go vet` + `gofmt` check + `go build` + `go test -race` + `shellcheck` + `goreleaser check` inside an `archlinux:latest` container on every push and PR.
+
+**Architecture:** One workflow file (`.gitea/workflows/ci.yml`), one job with sequential steps. The Arch container gives environmental fidelity; `actions/setup-go@v5` pins Go via `go-version-file: go.mod` for reproducibility.
+
+**Tech Stack:** Gitea Actions, archlinux:latest container, Go (version pinned in go.mod), shellcheck, goreleaser v2.
+
+**Spec:** `docs/superpowers/specs/2026-04-14-ci-workflow-design.md`
+
+---
+
+## File Structure
+
+**New files:**
+- `.gitea/workflows/ci.yml` — single-job CI workflow
+
+**No other files change.**
+
+---
+
+## Task 1: Pre-flight — verify all CI steps pass locally
+
+Before writing the workflow, run every command it will execute locally to confirm the repo is in a CI-passing state. If any command fails, either the plan's step is wrong or the repo has a latent issue — either way, CI will fail without this check.
+
+**Files:** none (validation only)
+
+- [ ] **Step 1: `go vet ./...`**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go vet ./...
+```
+
+Expected: exit 0, no output.
+
+If warnings appear, STOP and report — fixing them is out of scope for this plan but must happen before CI can land.
+
+- [ ] **Step 2: `gofmt` check**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+diff=$(gofmt -l .)
+if [ -n "$diff" ]; then echo "FILES NEEDING FMT:"; echo "$diff"; exit 1; fi
+echo "gofmt clean"
+```
+
+Expected: `gofmt clean`.
+
+If any files are listed, STOP and report. Fixing formatting is out of scope — do NOT auto-fix in this plan. The user should decide whether to format in a separate commit first.
+
+- [ ] **Step 3: `go build ./...`**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go build ./...
+```
+
+Expected: exit 0, no output.
+
+- [ ] **Step 4: `go test -race ./...`**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go test -race ./...
+```
+
+Expected: all packages report `ok` or `no test files`. Failures = STOP and report. Race detector findings = STOP and report (they indicate real concurrency bugs).
+
+- [ ] **Step 5: `shellcheck bootstrap.sh`**
+
+```bash
+command -v shellcheck || { echo "shellcheck not installed; install via: sudo pacman -S shellcheck"; exit 1; }
+shellcheck /home/marvin/git-clones/ArduinoArchSetup/bootstrap.sh
+```
+
+Expected: exit 0, no output.
+
+If shellcheck isn't installed locally, install it (`sudo pacman -S shellcheck`) and retry. If findings appear, STOP and report — bootstrap.sh was validated by `bash -n` only, so this is the first shellcheck run.
+
+- [ ] **Step 6: `goreleaser check`**
+
+```bash
+command -v goreleaser || command -v /home/marvin/go/bin/goreleaser || { echo "goreleaser missing"; exit 1; }
+(command -v goreleaser && goreleaser check) || /home/marvin/go/bin/goreleaser check
+```
+
+Expected: `• 1 configuration file(s) validated` or equivalent success message.
+
+- [ ] **Step 7: No commit**
+
+This task is informational. If all six steps passed, proceed to Task 2. If any failed, report findings to the controller and HALT — the CI workflow cannot land until the repo is in a passing state.
+
+---
+
+## Task 2: Author `.gitea/workflows/ci.yml`
+
+**Files:**
+- Create: `.gitea/workflows/ci.yml`
+
+- [ ] **Step 1: Write the workflow file**
+
+Create `/home/marvin/git-clones/ArduinoArchSetup/.gitea/workflows/ci.yml`:
+
+```yaml
+name: ci
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: archlinux:latest
+    steps:
+      - name: Install container prereqs
+        run: pacman -Sy --needed --noconfirm base-devel git shellcheck
+
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: go vet
+        run: go vet ./...
+
+      - name: gofmt check
+        run: |
+          diff=$(gofmt -l .)
+          if [ -n "$diff" ]; then
+            echo "files need gofmt:"
+            echo "$diff"
+            exit 1
+          fi
+
+      - name: go build
+        run: go build ./...
+
+      - name: go test -race
+        run: go test -race ./...
+
+      - name: shellcheck bootstrap.sh
+        run: shellcheck bootstrap.sh
+
+      - name: Install goreleaser
+        run: go install github.com/goreleaser/goreleaser/v2@latest
+
+      - name: goreleaser check
+        run: $(go env GOPATH)/bin/goreleaser check
+```
+
+- [ ] **Step 2: Validate YAML syntax**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+python3 -c "import yaml; yaml.safe_load(open('.gitea/workflows/ci.yml'))" && echo "yaml ok"
+```
+
+Expected: `yaml ok`.
+
+- [ ] **Step 3: Sanity-check step ordering against spec**
+
+Open the file and confirm the step order matches the spec's Section "Job steps":
+1. Install container prereqs
+2. Checkout
+3. Setup Go
+4. go vet
+5. gofmt check
+6. go build
+7. go test -race
+8. shellcheck bootstrap.sh
+9. Install goreleaser
+10. goreleaser check
+
+No grouping or reordering. This is only a human-verified check (no command).
+
+- [ ] **Step 4: Commit**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+git add .gitea/workflows/ci.yml
+git commit -m "ci: add Gitea Actions workflow for test, vet, fmt, build, shellcheck, goreleaser check"
+```
+
+Do NOT add any Co-Authored-By trailer — repo convention forbids it.
+
+---
+
+## Notes for the executing agent
+
+- **One file, one job.** Don't split into multiple jobs or multiple workflows. The spec is explicit.
+- **Do not try to run the workflow itself** — that requires a Gitea Actions runner (Plan 4c Task 9, currently deferred). The workflow will queue when pushed until a runner is online; that's fine.
+- **If Task 1 reveals failures** in `go vet`, `gofmt`, `go test -race`, or `shellcheck`, stop and escalate. Those are pre-existing issues the controller needs to address in a separate commit/plan; this plan only adds the workflow that detects them.
+- **Why `$(go env GOPATH)/bin/goreleaser` explicitly** in step 10: `go install` puts binaries in `GOPATH/bin`, which isn't on `$PATH` inside the stock Arch container. Using the absolute path is simpler than mutating PATH.
+- **YAML indentation is significant.** Use 2-space indents matching the example above. Do not substitute tabs.

docs/superpowers/plans/2026-04-14-force-reapply.md

@@ -0,0 +1,726 @@
+# Force Reapply Implementation Plan (Plan 4b)
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add `archduino install --force` that reapplies every selected module unconditionally — new `PlanForce` method on `module.Module`, new `Reinstall` helpers on `platform.Pacman`/`platform.Yay`, engine + wizard + CLI wiring.
+
+**Architecture:** Interface-level `PlanForce(ctx) (Plan, error)` gives each module an explicit "redo everything" path. Engine branches on `RunOptions.Force` to skip `Detect` and call `PlanForce`. Wizard mirrors that branch in its preview cache. Package-only modules reinstall without `--needed`; config-writing modules rewrite managed files.
+
+**Tech Stack:** Go, existing cobra + bubbletea stack. No new dependencies.
+
+**Spec:** `docs/superpowers/specs/2026-04-14-force-reapply-design.md`
+
+---
+
+## File Structure
+
+**Modified (no new files):**
+- `internal/platform/pacman.go` + `_test.go` — add `Reinstall`
+- `internal/platform/aur.go` + `_test.go` — add `Reinstall`
+- `internal/module/module.go` — add `PlanForce` to interface
+- `internal/engine/engine.go` + `_test.go` — add `RunOptions.Force`
+- `internal/tui/state.go` — add `WizardState.Force`
+- `internal/tui/wizard/wizard.go` + `_test.go` — force-aware preview
+- `cmd/archduino/main.go` — add `--force` flag
+- 13 module files + their tests — implement `PlanForce`
+
+---
+
+## Task 1: Platform layer — `Reinstall` on Pacman and Yay
+
+**Files:**
+- Modify: `internal/platform/pacman.go`
+- Modify: `internal/platform/pacman_test.go`
+- Modify: `internal/platform/aur.go`
+- Modify: `internal/platform/aur_test.go`
+
+- [ ] **Step 1: Inspect existing Install methods**
+
+Read the existing `Install` methods in `pacman.go` and `aur.go` to know their exact command construction. The new `Reinstall` must be identical except for the `--needed` flag being absent.
+
+```bash
+grep -n -A 15 "func.*Install" internal/platform/pacman.go internal/platform/aur.go
+```
+
+Read the test files to understand how commands are asserted (likely via `FakeRunner` recording executed commands).
+
+- [ ] **Step 2: Write failing test for `Pacman.Reinstall`**
+
+Add to `internal/platform/pacman_test.go`:
+
+```go
+func TestPacmanReinstall(t *testing.T) {
+	fr := &FakeRunner{}
+	p := NewPacman(fr)
+	if err := p.Reinstall(context.Background(), []string{"git", "curl"}); err != nil {
+		t.Fatalf("Reinstall: %v", err)
+	}
+	if len(fr.Calls) != 1 {
+		t.Fatalf("expected 1 call, got %d", len(fr.Calls))
+	}
+	got := fr.Calls[0]
+	// Must include -S and --noconfirm but NOT --needed.
+	if !containsAll(got.Args, "-S", "--noconfirm") {
+		t.Errorf("expected -S and --noconfirm in args; got %v", got.Args)
+	}
+	for _, a := range got.Args {
+		if a == "--needed" {
+			t.Errorf("Reinstall must not pass --needed; got args %v", got.Args)
+		}
+	}
+	if !containsAll(got.Args, "git", "curl") {
+		t.Errorf("expected packages git, curl in args; got %v", got.Args)
+	}
+}
+```
+
+Adjust `containsAll` / `FakeRunner` / `Calls` field names to match what the existing tests already use. Read `pacman_test.go` first to confirm the exact helper names — do NOT invent names.
+
+- [ ] **Step 3: Run test, verify it fails**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go test ./internal/platform/ -run TestPacmanReinstall -v
+```
+
+Expected: FAIL with `undefined: Pacman.Reinstall` or similar.
+
+- [ ] **Step 4: Implement `Pacman.Reinstall`**
+
+Add to `internal/platform/pacman.go`, mirroring the existing `Install`:
+
+```go
+// Reinstall runs `pacman -S --noconfirm pkg...` without --needed so pacman
+// unconditionally reinstalls each package. Used by force-reapply.
+func (p Pacman) Reinstall(ctx context.Context, pkgs []string) error {
+	if len(pkgs) == 0 {
+		return nil
+	}
+	args := append([]string{"pacman", "-S", "--noconfirm"}, pkgs...)
+	return p.runner.RunSudo(ctx, args[0], args[1:]...)
+}
+```
+
+Adjust the runner method (`RunSudo` / `Run`) to whatever the existing `Install` uses. Read `Install` first.
+
+- [ ] **Step 5: Run test, verify it passes**
+
+```bash
+go test ./internal/platform/ -run TestPacmanReinstall -v
+```
+
+Expected: PASS.
+
+- [ ] **Step 6: Repeat Steps 2–5 for `Yay.Reinstall`**
+
+Add `TestYayReinstall` to `internal/platform/aur_test.go` (parallel structure; `yay` command instead of `pacman`). Then implement `Yay.Reinstall` in `aur.go`. Run `go test ./internal/platform/ -run TestYayReinstall -v`, verify it passes.
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add internal/platform/pacman.go internal/platform/pacman_test.go \
+        internal/platform/aur.go internal/platform/aur_test.go
+git commit -m "feat(platform): add Reinstall helpers to Pacman and Yay"
+```
+
+No Co-Authored-By trailer.
+
+---
+
+## Task 2: Extend Module interface + stub all 13 modules
+
+Adding `PlanForce` to the interface breaks compilation until every module implements it. This task adds the interface method and a *stub* implementation on every module that returns `module.Plan{}, errors.New("PlanForce not implemented")`. Compilation stays green, engine is not wired yet, and each module's real implementation lands in a later task with its own test.
+
+**Files:**
+- Modify: `internal/module/module.go`
+- Modify: 13 module files listed below
+
+- [ ] **Step 1: Add `PlanForce` to the interface**
+
+Edit `internal/module/module.go`. In the `Module` interface block:
+
+```go
+type Module interface {
+	Meta() Meta
+	Detect(ctx context.Context) (State, error)
+	Plan(ctx context.Context, current State) (Plan, error)
+	PlanForce(ctx context.Context) (Plan, error)
+	Apply(ctx context.Context, plan Plan, r Reporter) error
+	Verify(ctx context.Context) error
+}
+```
+
+Add a doc comment above `PlanForce`:
+
+```go
+	// PlanForce returns a plan that reapplies the module unconditionally,
+	// ignoring current detected state. Used by `archduino install --force`.
+	// Implementations should produce a plan equivalent to a from-scratch
+	// install — reinstall packages without pacman's --needed guard and
+	// rewrite managed config files.
+```
+
+- [ ] **Step 2: Verify compile fails**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go build ./... 2>&1 | head -20
+```
+
+Expected: compile errors like `*starship.Module does not implement module.Module (missing method PlanForce)` for every module.
+
+- [ ] **Step 3: Add stub `PlanForce` to every module**
+
+For each of the 13 module files below, append this stub at the bottom of the file (replace `Module` receiver type if the file uses something different — read each file first to confirm):
+
+```go
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	return module.Plan{}, errors.New("PlanForce not implemented")
+}
+```
+
+Ensure `errors` is imported. The module files:
+
+1. `internal/modules/packages/packages.go`
+2. `internal/modules/gittools/gittools.go`
+3. `internal/modules/fonts/fonts.go`
+4. `internal/modules/renode/renode.go`
+5. `internal/modules/hello/hello.go`
+6. `internal/modules/starship/starship.go`
+7. `internal/modules/yazi/yazi.go`
+8. `internal/modules/zsh/zsh.go`
+9. `internal/modules/zellij/zellij.go`
+10. `internal/modules/shellconfig/shellconfig.go`
+11. `internal/modules/themes/themes.go`
+12. `internal/modules/neovim/neovim.go`
+13. `internal/modules/arduinocli/arduinocli.go`
+
+- [ ] **Step 4: Verify compile + existing tests pass**
+
+```bash
+go build ./...
+go test ./...
+```
+
+Expected: compile clean, all existing tests green. The new stubs aren't exercised yet.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add internal/module/module.go internal/modules/
+git commit -m "feat(module): add PlanForce to Module interface with stubs"
+```
+
+---
+
+## Task 3: Engine — `RunOptions.Force` + branch
+
+**Files:**
+- Modify: `internal/engine/engine.go`
+- Modify: `internal/engine/engine_test.go`
+
+- [ ] **Step 1: Write failing test**
+
+In `internal/engine/engine_test.go`, add:
+
+```go
+func TestRunForceSkipsDetectAndCallsPlanForce(t *testing.T) {
+	fake := &fakeModule{
+		id:       "fake",
+		planForce: module.Plan{Actions: []module.Action{{
+			Description: "forced action",
+			Exec:        func(ctx context.Context) error { return nil },
+		}}},
+	}
+	reg := module.NewRegistry()
+	if err := reg.Register(fake); err != nil {
+		t.Fatal(err)
+	}
+	var buf bytes.Buffer
+	sum, err := engine.Run(context.Background(), reg, engine.RunOptions{
+		Selected: []string{"fake"},
+		Force:    true,
+		Reporter: engine.NewPlainReporter(&buf),
+	})
+	if err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+	if fake.detectCalls != 0 {
+		t.Errorf("Detect should not be called under Force; got %d calls", fake.detectCalls)
+	}
+	if fake.planForceCalls != 1 {
+		t.Errorf("PlanForce should be called once; got %d", fake.planForceCalls)
+	}
+	if fake.planCalls != 0 {
+		t.Errorf("Plan should not be called under Force; got %d", fake.planCalls)
+	}
+	if sum.Applied != 1 {
+		t.Errorf("expected Applied=1, got %d", sum.Applied)
+	}
+}
+```
+
+`fakeModule` already exists in `engine_test.go`; extend it with:
+- `planForce module.Plan`
+- `planForceCalls int`
+- Implement `PlanForce(ctx) (module.Plan, error)` that increments the counter and returns `planForce`.
+- If `detectCalls`/`planCalls` don't already exist on the fake, add them too (they may already be there — read the file first).
+
+Read `engine_test.go` before editing to confirm the fake's field layout.
+
+- [ ] **Step 2: Run test, verify it fails**
+
+```bash
+go test ./internal/engine/ -run TestRunForceSkipsDetectAndCallsPlanForce -v
+```
+
+Expected: FAIL — likely `unknown field Force in RunOptions` at compile time.
+
+- [ ] **Step 3: Add `Force` to `RunOptions`**
+
+In `internal/engine/engine.go`, find the `RunOptions` struct and add:
+
+```go
+// Force, when true, skips Detect and calls PlanForce on every module
+// so each one produces a from-scratch plan regardless of current state.
+Force bool
+```
+
+- [ ] **Step 4: Branch `Run` on `Force`**
+
+Find the per-module loop inside `Run`. The current shape is roughly:
+
+```go
+cur, err := mod.Detect(ctx)
+if err != nil { /* handle */ }
+plan, err := mod.Plan(ctx, cur)
+```
+
+Replace with:
+
+```go
+var (
+	plan module.Plan
+	err  error
+)
+if opts.Force {
+	plan, err = mod.PlanForce(ctx)
+} else {
+	cur, derr := mod.Detect(ctx)
+	if derr != nil {
+		// preserve existing Detect error handling verbatim
+		err = derr
+	} else {
+		plan, err = mod.Plan(ctx, cur)
+	}
+}
+```
+
+Read the current block first and preserve its error-handling shape (reporter calls, halt-on-error, summary bookkeeping). Do not inline a different handling style.
+
+- [ ] **Step 5: Run test, verify it passes**
+
+```bash
+go test ./internal/engine/ -run TestRunForceSkipsDetectAndCallsPlanForce -v
+go test ./internal/engine/ -v
+```
+
+Expected: both green.
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add internal/engine/engine.go internal/engine/engine_test.go
+git commit -m "feat(engine): add RunOptions.Force to skip Detect and call PlanForce"
+```
+
+---
+
+## Task 4: Package-only modules — real `PlanForce`
+
+Package-only modules' `PlanForce` produces a plan that calls `Reinstall` on the full package list.
+
+**Modules covered:** `packages`, `gittools`, `fonts`, `renode`, `hello`.
+
+**Files:** for each module, both `<name>.go` and `<name>_test.go`.
+
+For the four real modules (packages, gittools, fonts, renode), follow the same pattern. Do this **one module at a time** (5 cycles of write-test → verify-fail → implement → verify-pass → next). For `hello`, since it's a placeholder, make `PlanForce` return a fixed non-empty plan (see below).
+
+### Pattern (use for each of packages / gittools / fonts / renode)
+
+- [ ] **Step 1: Write failing `TestPlanForce` in the module's `_test.go`**
+
+Template (adapt field names to the module under test — read the existing `TestPlan` test for each module to see how the fake pacman/yay is wired):
+
+```go
+func TestPlanForceReinstallsAllPackages(t *testing.T) {
+	fp := &FakePacman{installed: map[string]bool{"git": true, "curl": true}}
+	m := New([]string{"git", "curl"}, fp)
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty even when packages are installed")
+	}
+	// Execute to confirm it calls Reinstall, not Install.
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	if fp.ReinstallCalls != 1 {
+		t.Errorf("expected 1 Reinstall call, got %d", fp.ReinstallCalls)
+	}
+}
+```
+
+If `FakePacman` doesn't already have a `ReinstallCalls` counter and a `Reinstall` method, add them to the fake first (read the fake in the same test file — most modules share a local fake or use a common one in `internal/platform`).
+
+- [ ] **Step 2: Run test, verify it fails**
+
+```bash
+go test ./internal/modules/<name>/ -run TestPlanForce -v
+```
+
+Expected: FAIL — the stub returns an error.
+
+- [ ] **Step 3: Replace stub with real `PlanForce`**
+
+In `<name>.go`, replace the stub with (adjust receiver/field names):
+
+```go
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.pkgs) == 0 {
+		return module.Plan{}, nil
+	}
+	pkgs := append([]string{}, m.pkgs...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+	}}}, nil
+}
+```
+
+Ensure the module's stored `pm` field (or equivalent) has the `Reinstall` method available — it will, because Task 1 added it to both `Pacman` and `Yay`, and the fake was extended in Step 1.
+
+- [ ] **Step 4: Run test, verify it passes**
+
+```bash
+go test ./internal/modules/<name>/ -v
+```
+
+Expected: PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add internal/modules/<name>/
+git commit -m "feat(<name>): implement PlanForce to reinstall all packages"
+```
+
+### `hello` module
+
+The `hello` module is a placeholder. Implement `PlanForce` as:
+
+```go
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	return module.Plan{Actions: []module.Action{{
+		Description: "hello force reapply",
+		Exec:        func(ctx context.Context) error { return nil },
+	}}}, nil
+}
+```
+
+Add a test that just asserts the plan is non-empty. Same commit cadence as above.
+
+- [ ] **Step 6: Complete all 5 modules before moving on**
+
+After each of packages / gittools / fonts / renode / hello has its own commit, move to Task 5. Do NOT batch them into one commit.
+
+---
+
+## Task 5: Hybrid modules — `starship`, `yazi`
+
+These modules install packages AND (optionally) write configs. Their existing `Plan` already produces a plan that may include both; `PlanForce` should produce both unconditionally.
+
+For each of `starship` and `yazi`:
+
+- [ ] **Step 1: Read the existing `Plan` to see what it does**
+
+```bash
+grep -n -A 30 "func.*Module.*Plan\b" internal/modules/starship/starship.go
+grep -n -A 30 "func.*Module.*Plan\b" internal/modules/yazi/yazi.go
+```
+
+Identify the branches: package install vs. config write (if any).
+
+- [ ] **Step 2: Write failing `TestPlanForce`**
+
+The test must arrange a "fully satisfied" state (packages installed, any config files already present) and assert the force plan is non-empty AND its actions reinstall the packages (via Reinstall call counter) AND rewrite the config files (via a writefile call counter or file presence assertion).
+
+Use the same pattern as Task 4 for the package side. For the config side, use whatever the module's existing tests use to assert config writes (likely `WriteFile` mock or a tempdir).
+
+- [ ] **Step 3: Run test, verify it fails**
+
+```bash
+go test ./internal/modules/<name>/ -run TestPlanForce -v
+```
+
+- [ ] **Step 4: Replace stub with real `PlanForce`**
+
+```go
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	var actions []module.Action
+	if len(m.pkgs) > 0 {
+		pkgs := append([]string{}, m.pkgs...)
+		actions = append(actions, module.Action{
+			Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+		})
+	}
+	// Any config-write actions the module normally conditions on Detect:
+	actions = append(actions, /* unconditional config-write actions */ ...)
+	return module.Plan{Actions: actions}, nil
+}
+```
+
+Fill in the config-write actions by lifting them from `Plan` but stripping the "already exists" short-circuit. Reuse the same helper functions (e.g. `writeConfig`) that `Plan` uses.
+
+- [ ] **Step 5: Run test, verify it passes, commit**
+
+```bash
+go test ./internal/modules/<name>/ -v
+git add internal/modules/<name>/
+git commit -m "feat(<name>): implement PlanForce (reinstall + rewrite config)"
+```
+
+Repeat for both modules, one commit each.
+
+---
+
+## Task 6: Config-writing simple modules — `zsh`, `zellij`, `shellconfig`, `themes`
+
+Same pattern as Task 5 — read existing `Plan`, lift its actions, strip conditionals. Do one module per commit.
+
+For each of `zsh`, `zellij`, `shellconfig`, `themes`:
+
+- [ ] **Step 1: Write failing `TestPlanForce`** — satisfied-system fixture → assert non-empty plan with all the module's write/install actions.
+- [ ] **Step 2: Run test, verify it fails.**
+- [ ] **Step 3: Replace stub with real implementation.**
+- [ ] **Step 4: Run test, verify it passes.**
+- [ ] **Step 5: Commit** with message `feat(<name>): implement PlanForce`.
+
+Module-specific notes:
+
+- **`shellconfig`** has no packages; `PlanForce` only produces file-write actions.
+- **`themes`** writes under `~/.config/archduino/overlay.yaml` — force rewrites the overlay's theme fields unconditionally.
+- **`zsh`** clones plugins (oh-my-zsh, etc.) via `git`; `PlanForce` should clone even if the target already exists — add a pre-step that removes the directory, or use the `git` helper's `ForceClone` if one exists (grep `internal/platform/git.go`; if missing, note it as a concern and fall back to rm-then-clone via an action that uses `os.RemoveAll` before the clone).
+
+---
+
+## Task 7: Config-writing complex modules — `neovim`, `arduinocli`
+
+Same pattern as Task 6, but these modules have multiple sub-steps (neovim: clone NvChad, write chadrc, run post-install; arduinocli: install binary, update index, install cores, install libraries).
+
+For each module:
+
+- [ ] **Step 1: Enumerate the existing `Plan`'s sub-actions.** Every conditional "already done" branch in `Plan` becomes an unconditional branch in `PlanForce`.
+- [ ] **Step 2: Write failing `TestPlanForce`** — satisfied-system fixture → assert ALL sub-actions are present (count-based is fine if exact equality is fragile).
+- [ ] **Step 3: Run test, verify it fails.**
+- [ ] **Step 4: Replace stub with real implementation.**
+- [ ] **Step 5: Run test, verify it passes.**
+- [ ] **Step 6: Commit** with message `feat(<name>): implement PlanForce`.
+
+**Neovim specifics:**
+- If `NvChad` is already cloned, `PlanForce` should either `git pull` + rewrite `chadrc.lua` OR `rm -rf && git clone`. Pick the simpler: rewrite `chadrc.lua` unconditionally, do NOT delete the existing clone. Users' local NvChad modifications shouldn't be wiped by `--force`. Document this in a code comment.
+
+**arduinocli specifics:**
+- `PlanForce` should re-download the binary tarball, re-run `arduino-cli core update-index`, and re-install every configured core/library regardless of current installation. Cores install is idempotent at the arduino-cli layer; no issue.
+
+---
+
+## Task 8: TUI wizard — force-aware preview
+
+**Files:**
+- Modify: `internal/tui/state.go`
+- Modify: `internal/tui/wizard/wizard.go`
+- Modify: `internal/tui/wizard/wizard_test.go`
+
+- [ ] **Step 1: Add `Force bool` to `WizardState`**
+
+In `internal/tui/state.go`, find the `WizardState` struct (or wherever the wizard's global state lives) and add a `Force bool` field with a doc comment:
+
+```go
+// Force mirrors the --force CLI flag: when true, the wizard's per-module
+// plan preview uses PlanForce instead of Detect + Plan, and the header
+// shows a "Force mode" banner.
+Force bool
+```
+
+If `WizardState` is constructed in a factory (e.g., `NewWizardState(cfg, reg)`), leave the constructor signature alone — the flag is set by the CLI after construction.
+
+- [ ] **Step 2: Write failing test for wizard preview under force**
+
+In `internal/tui/wizard/wizard_test.go`, add a test that dispatches the wizard's plan-preview code path with `Force: true` on a fake module whose `Detect` panics (proving it's not called) and whose `PlanForce` returns a non-empty plan.
+
+The exact test shape depends on how the wizard currently tests previews — read the existing preview tests before writing. Bare minimum:
+
+```go
+func TestWizardPreviewUsesPlanForceWhenForceSet(t *testing.T) {
+	mod := &fakeModule{
+		planForce: module.Plan{Actions: []module.Action{{Description: "forced"}}},
+		detect:    func() (module.State, error) { t.Fatal("Detect should not be called"); return nil, nil },
+	}
+	// ... drive the preview path and assert the displayed plan is the PlanForce output
+}
+```
+
+- [ ] **Step 3: Run test, verify it fails**
+
+```bash
+go test ./internal/tui/wizard/ -run TestWizardPreviewUsesPlanForceWhenForceSet -v
+```
+
+- [ ] **Step 4: Branch the preview cache on `Force`**
+
+In `internal/tui/wizard/wizard.go`, find the `planCache` / preview logic (Plan 3a Task 1 added this — search for `planCache` or `Detect` call sites inside the wizard). Add a branch:
+
+```go
+if state.Force {
+	plan, err = mod.PlanForce(ctx)
+} else {
+	cur, derr := mod.Detect(ctx)
+	if derr != nil { /* existing error path */ }
+	plan, err = mod.Plan(ctx, cur)
+}
+```
+
+Also: the cache key must include `force` so a force run doesn't reuse a non-force cached plan. If the cache is keyed by module ID only today, extend it to `(moduleID, force)`.
+
+- [ ] **Step 5: Add a header banner**
+
+Find the wizard's view/render code (likely a `View()` method). When `state.Force`, prepend a banner line to the rendered output:
+
+```go
+if state.Force {
+	sb.WriteString(styles.Warning.Render("⚠ Force mode: all selected modules will be reapplied"))
+	sb.WriteString("\n\n")
+}
+```
+
+Use whatever Lipgloss style the codebase already has for warnings (grep for `Warning`, `warnStyle`, or similar). If none exists, use a plain bold-red or bold string — do NOT create a new style module just for this.
+
+- [ ] **Step 6: Run test, verify it passes + rest of wizard tests**
+
+```bash
+go test ./internal/tui/wizard/ -v
+go test ./internal/tui/ -v
+```
+
+Expected: all green.
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add internal/tui/state.go internal/tui/wizard/
+git commit -m "feat(tui): wizard uses PlanForce preview when Force is set"
+```
+
+---
+
+## Task 9: CLI — `--force` flag
+
+**Files:**
+- Modify: `cmd/archduino/main.go`
+
+- [ ] **Step 1: Add the flag**
+
+In `newInstallCmd`, alongside the other flag declarations (`noTUI`, `dryRun`, `halt`, `noSudo`, `only`, `skip`, `overlayPath`), add:
+
+```go
+var force bool
+// ...
+cmd.Flags().BoolVar(&force, "force", false,
+    "Reapply every selected module, ignoring current state")
+```
+
+- [ ] **Step 2: Propagate to engine and wizard**
+
+In the `RunE` body:
+- Where `engine.RunOptions{…}` is constructed (there are currently two call sites: no-TUI path and TUI path — both must set `Force: force`).
+- Where `tui.NewWizardState(cfg, reg)` is called: after construction, set `initial.Force = force`.
+
+- [ ] **Step 3: Smoke-test**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go build ./cmd/archduino
+./archduino install --help | grep -A 2 force
+./archduino install --force --dry-run --no-tui --no-sudo 2>&1 | head -20
+```
+
+Expected: `--help` shows the new flag; a dry-run with `--force` completes without error and prints per-module force plans.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add cmd/archduino/main.go
+git commit -m "feat(cmd): add --force flag to install command"
+```
+
+---
+
+## Task 10: End-to-end validation
+
+**Files:** none (validation only)
+
+- [ ] **Step 1: Full test suite with race detector**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go test -race ./...
+```
+
+Expected: every package `ok`. Failures here = STOP and fix.
+
+- [ ] **Step 2: Full build**
+
+```bash
+go build ./...
+```
+
+Expected: exit 0.
+
+- [ ] **Step 3: gofmt + vet**
+
+```bash
+diff=$(gofmt -l .); [ -z "$diff" ] && echo "gofmt clean" || { echo "$diff"; exit 1; }
+go vet ./...
+```
+
+Expected: both clean.
+
+- [ ] **Step 4: Dry-run smoke (without and with force)**
+
+```bash
+./archduino install --dry-run --no-tui --no-sudo 2>&1 | tail -10
+./archduino install --dry-run --no-tui --no-sudo --force 2>&1 | tail -10
+```
+
+Expected: second output's per-module plan is non-empty for every selected module (even ones the first output reports as satisfied).
+
+- [ ] **Step 5: No commit — validation is informational**
+
+---
+
+## Notes for the executing agent
+
+- **Interface change order matters.** Task 2's stubs MUST land before any per-module `PlanForce` test runs (Task 3 onward), otherwise the whole package is red.
+- **Read each module's existing `Plan` before writing `PlanForce`.** The force version is almost always "strip the conditionals from Plan". Don't invent new actions.
+- **Do not delete users' cloned repos during force.** Especially neovim's NvChad clone. Rewriting `chadrc.lua` is enough; use `git pull` if the user wants updates, not `rm -rf && git clone`.
+- **If a module's test file doesn't already have a fake pacman/yay with a `Reinstall` method,** extend the fake in that file (or, if it lives in `internal/platform/testing.go` or similar, extend it once there). Do NOT duplicate fakes — reuse.
+- **Conventional Commits:** every module's force implementation gets its own `feat(<name>):` commit. This keeps the changelog readable and svu happy.
+- **CI is now live** (Plan 4d merged into this branch). Expect the workflow to run on every push of this plan — if it goes red, the task isn't done.

docs/superpowers/plans/2026-04-14-release-pipeline.md

@@ -0,0 +1,789 @@
+# Release Pipeline Implementation Plan (Plan 4c)
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Ship versioned Archduino releases to self-hosted Gitea with one-command `make release`, and let users install via `curl | bash`.
+
+**Architecture:** `bootstrap.sh` (curl-piped installer) + `.goreleaser.yaml` (cross-compile/archive/publish) + `Makefile` (svu-driven bump) + `.gitea/workflows/release.yml` (tag-triggered CI). Binary version injected via `-ldflags` into existing `main.version` var.
+
+**Tech Stack:** Go 1.x, goreleaser v2, svu, Gitea Actions, cobra (already in tree).
+
+**Spec:** `docs/superpowers/specs/2026-04-14-release-pipeline-design.md`
+
+---
+
+## File Structure
+
+**New files:**
+- `bootstrap.sh` — curl-piped installer
+- `.goreleaser.yaml` — goreleaser config
+- `Makefile` — release/snapshot/completions/build targets
+- `.gitea/workflows/release.yml` — tag-triggered release workflow
+- `LICENSE` — repo license (MIT; confirm with user during Task 7)
+- `.gitignore` additions: `dist/`, `completions/`
+
+**Modified files:**
+- `cmd/archduino/main.go` — add `commit`/`date` ldflag-injected vars; ensure `version` cobra subcommand prints them; ensure `completion` subcommand registered
+- `README.md` — install-via-bootstrap section, `svu` dev note
+
+**Removed/archived files:**
+- `install.sh` → `install.sh.legacy` (kept for reference, renamed so it's not confused with entry point)
+
+---
+
+## Task 1: Build-info ldflag wiring + version subcommand
+
+**Files:**
+- Modify: `cmd/archduino/main.go`
+- Test: manual smoke (no Go test — version output is a trivial glue)
+
+- [ ] **Step 1: Add commit/date vars and `version` subcommand**
+
+Edit `cmd/archduino/main.go`. Change the `version` declaration and add two new package-level vars just below it:
+
+```go
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
+)
+```
+
+Add a `newVersionCmd` function at the bottom of the file:
+
+```go
+func newVersionCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "version",
+		Short: "Print version, commit, and build date",
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Printf("archduino %s\ncommit: %s\ndate:   %s\n", version, commit, date)
+		},
+	}
+}
+```
+
+Register it in `main()` alongside the other `root.AddCommand` calls:
+
+```go
+root.AddCommand(newVersionCmd())
+```
+
+- [ ] **Step 2: Verify `completion` subcommand is available**
+
+Cobra registers a `completion` command automatically unless disabled. Run:
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+go run ./cmd/archduino completion bash | head -5
+```
+
+Expected: bash completion script output (starts with `# bash completion V2 for archduino`).
+
+If the command is missing, it means `CompletionOptions.DisableDefaultCmd` was set somewhere — grep for it and remove.
+
+- [ ] **Step 3: Smoke-test the version command**
+
+```bash
+go run ./cmd/archduino version
+```
+
+Expected output:
+```
+archduino dev
+commit: none
+date:   unknown
+```
+
+Then verify ldflag injection works:
+```bash
+go run -ldflags "-X main.version=v0.9.9 -X main.commit=abc123 -X main.date=2026-04-14" ./cmd/archduino version
+```
+
+Expected:
+```
+archduino v0.9.9
+commit: abc123
+date:   2026-04-14
+```
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add cmd/archduino/main.go
+git commit -m "feat(cmd): add version subcommand with ldflag-injected build info"
+```
+
+---
+
+## Task 2: .gitignore + LICENSE + completions dir
+
+**Files:**
+- Modify: `.gitignore`
+- Create: `LICENSE`
+- Create: `completions/.gitkeep`
+
+- [ ] **Step 1: Update .gitignore**
+
+Append to `.gitignore` (create the file if missing):
+
+```
+# goreleaser output
+dist/
+
+# generated shell completions
+completions/
+```
+
+- [ ] **Step 2: Ask user for LICENSE choice**
+
+Before writing `LICENSE`, pause and ask the user which license (MIT, Apache-2.0, GPL-3.0, etc.). Default suggestion: MIT. Do not proceed with a guess.
+
+Once confirmed, write `LICENSE` with the standard text for the chosen license. For MIT:
+
+```
+MIT License
+
+Copyright (c) 2026 MDietermann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+```
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add .gitignore LICENSE
+git commit -m "chore: add LICENSE and ignore dist/ and completions/"
+```
+
+---
+
+## Task 3: .goreleaser.yaml
+
+**Files:**
+- Create: `.goreleaser.yaml`
+
+- [ ] **Step 1: Write the goreleaser config**
+
+Create `.goreleaser.yaml`:
+
+```yaml
+version: 2
+
+project_name: archduino
+
+before:
+  hooks:
+    - mkdir -p completions
+    - sh -c "go run ./cmd/archduino completion bash > completions/archduino.bash"
+    - sh -c "go run ./cmd/archduino completion zsh  > completions/_archduino"
+    - sh -c "go run ./cmd/archduino completion fish > completions/archduino.fish"
+
+builds:
+  - id: archduino
+    main: ./cmd/archduino
+    binary: archduino
+    env:
+      - CGO_ENABLED=0
+    goos:
+      - linux
+    goarch:
+      - amd64
+      - arm64
+    ldflags:
+      - -s -w
+      - -X main.version={{ .Version }}
+      - -X main.commit={{ .Commit }}
+      - -X main.date={{ .Date }}
+
+archives:
+  - id: default
+    name_template: "archduino_{{ .Version }}_linux_{{ .Arch }}"
+    formats: [tar.gz]
+    files:
+      - README.md
+      - LICENSE
+      - src: completions/archduino.bash
+        dst: completions/archduino.bash
+      - src: completions/_archduino
+        dst: completions/_archduino
+      - src: completions/archduino.fish
+        dst: completions/archduino.fish
+
+checksum:
+  name_template: "checksums.txt"
+  algorithm: sha256
+
+changelog:
+  use: git
+  sort: asc
+  filters:
+    exclude:
+      - '^chore:'
+      - '^docs:'
+      - '^test:'
+      - '^ci:'
+      - '^style:'
+      - '^refactor:'
+      - 'Merge pull request'
+      - 'Merge branch'
+  groups:
+    - title: Features
+      regexp: '^feat(\(.*\))?:'
+      order: 0
+    - title: Bug fixes
+      regexp: '^(fix|perf)(\(.*\))?:'
+      order: 1
+    - title: Others
+      order: 999
+
+release:
+  gitea_urls:
+    api: https://gitlab.hive-brain.de/api/v1
+    download: https://gitlab.hive-brain.de
+  draft: false
+  prerelease: auto
+```
+
+- [ ] **Step 2: Install goreleaser locally if not present**
+
+```bash
+command -v goreleaser || go install github.com/goreleaser/goreleaser/v2@latest
+goreleaser --version
+```
+
+Expected: prints a version ≥ v2.
+
+- [ ] **Step 3: Validate the config**
+
+```bash
+cd /home/marvin/git-clones/ArduinoArchSetup
+goreleaser check
+```
+
+Expected: `• config is valid`. If errors, fix them before proceeding.
+
+- [ ] **Step 4: Run a snapshot build**
+
+```bash
+goreleaser release --snapshot --clean
+```
+
+Expected: `dist/` populated with two tar.gz archives (`archduino_*_linux_amd64.tar.gz`, `archduino_*_linux_arm64.tar.gz`), `checksums.txt`, and extracted binary subdirs. No errors.
+
+- [ ] **Step 5: Inspect archive contents**
+
+```bash
+tar -tzf dist/archduino_*_linux_amd64.tar.gz
+```
+
+Expected file list: `archduino`, `README.md`, `LICENSE`, `completions/archduino.bash`, `completions/_archduino`, `completions/archduino.fish`.
+
+- [ ] **Step 6: Verify binary has injected version**
+
+```bash
+tar -xzf dist/archduino_*_linux_amd64.tar.gz -C /tmp/archduino-smoke --one-top-level
+/tmp/archduino-smoke/archduino_*_linux_amd64/archduino version
+```
+
+Expected: prints a snapshot version (looks like `0.0.0-next-<commit>` or similar) and a real commit + date.
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add .goreleaser.yaml
+git commit -m "build: add goreleaser config for Gitea releases"
+```
+
+---
+
+## Task 4: Makefile
+
+**Files:**
+- Create: `Makefile`
+
+- [ ] **Step 1: Install svu locally**
+
+```bash
+command -v svu || go install github.com/caarlos0/svu@latest
+svu --version
+```
+
+Expected: prints a version.
+
+- [ ] **Step 2: Write the Makefile**
+
+Create `Makefile`:
+
+```makefile
+.PHONY: build snapshot release completions clean help
+
+GO ?= go
+BIN := archduino
+
+help: ## Show this help
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "  %-14s %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+
+build: ## Local dev build into ./archduino
+	$(GO) build -o $(BIN) ./cmd/archduino
+
+completions: ## Regenerate shell completions into completions/
+	@mkdir -p completions
+	$(GO) run ./cmd/archduino completion bash > completions/archduino.bash
+	$(GO) run ./cmd/archduino completion zsh  > completions/_archduino
+	$(GO) run ./cmd/archduino completion fish > completions/archduino.fish
+
+snapshot: ## Local goreleaser dry run into dist/
+	goreleaser release --snapshot --clean
+
+clean: ## Remove build artifacts
+	rm -rf dist/ completions/ $(BIN)
+
+release: ## Compute next SemVer from commits, tag, and push
+	@command -v svu >/dev/null || { echo "svu not found. Run: go install github.com/caarlos0/svu@latest"; exit 1; }
+	@test -z "$$(git status --porcelain)" || { echo "working tree is dirty; commit or stash first"; exit 1; }
+	@branch=$$(git rev-parse --abbrev-ref HEAD); \
+	 if [ "$$branch" != "master" ]; then echo "must be on master (currently on $$branch)"; exit 1; fi
+	@current=$$(svu current 2>/dev/null || echo "none"); \
+	 next=$$(svu next); \
+	 echo "Current: $$current"; \
+	 echo "Next:    $$next"; \
+	 echo; \
+	 echo "Commits since $$current:"; \
+	 if [ "$$current" = "none" ]; then git log --oneline; else git log --oneline $$current..HEAD; fi; \
+	 echo; \
+	 printf "Tag %s and push? [y/N] " "$$next"; read ans; \
+	 if [ "$$ans" != "y" ] && [ "$$ans" != "Y" ]; then echo "aborted"; exit 1; fi; \
+	 git tag "$$next" && git push origin "$$next"
+```
+
+- [ ] **Step 3: Smoke-test non-destructive targets**
+
+```bash
+make help
+make build && ./archduino version
+make completions && ls completions/
+```
+
+Expected: `help` lists targets; `build` produces `./archduino`; `completions` generates three files.
+
+- [ ] **Step 4: Dry-run the release guard**
+
+```bash
+# With dirty tree (touch a file first if tree is clean)
+touch /tmp/dirt && make release || echo "guard worked as expected"
+```
+
+Expected: aborts with "working tree is dirty". Do NOT actually run `make release` to completion yet — that creates a real tag.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add Makefile
+git commit -m "build: add Makefile with release, snapshot, completions targets"
+```
+
+---
+
+## Task 5: bootstrap.sh
+
+**Files:**
+- Create: `bootstrap.sh`
+
+- [ ] **Step 1: Write bootstrap.sh**
+
+Create `bootstrap.sh`:
+
+```bash
+#!/usr/bin/env bash
+set -euo pipefail
+
+REPO="MDietermann/Archduino"
+BASE_URL="${ARCHDUINO_RELEASE_BASE:-https://gitlab.hive-brain.de}"
+API_URL="${BASE_URL}/api/v1"
+
+err() { echo "bootstrap: error: $*" >&2; exit 1; }
+msg() { echo "==> $*"; }
+
+# Arch gate
+[ -f /etc/arch-release ] || err "Archduino v1 supports Arch Linux only."
+
+# Arch detect
+case "$(uname -m)" in
+  x86_64)  ARCH="amd64" ;;
+  aarch64) ARCH="arm64" ;;
+  *)       err "unsupported architecture: $(uname -m)" ;;
+esac
+
+# Prereqs
+msg "Installing prerequisites (sudo, git, curl, ca-certificates)"
+sudo pacman -Sy --needed --noconfirm sudo git curl ca-certificates
+
+# Discover latest release
+msg "Querying latest release from Gitea"
+API_ENDPOINT="${API_URL}/repos/${REPO}/releases/latest"
+RELEASE_JSON=$(curl -fsSL "$API_ENDPOINT") || err "failed to fetch ${API_ENDPOINT}"
+
+# Extract tag_name without requiring jq
+TAG=$(printf '%s' "$RELEASE_JSON" | grep -o '"tag_name":[[:space:]]*"[^"]*"' | head -1 | sed 's/.*"\([^"]*\)"$/\1/')
+[ -n "$TAG" ] || err "could not parse tag_name from release metadata"
+VERSION="${TAG#v}"
+msg "Latest release: ${TAG}"
+
+# Download
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+TARBALL="archduino_${VERSION}_linux_${ARCH}.tar.gz"
+CHECKSUMS="checksums.txt"
+DL_BASE="${BASE_URL}/${REPO}/releases/download/${TAG}"
+
+msg "Downloading ${TARBALL}"
+curl -fsSL -o "${TMP}/${TARBALL}"  "${DL_BASE}/${TARBALL}"  || err "tarball download failed"
+curl -fsSL -o "${TMP}/${CHECKSUMS}" "${DL_BASE}/${CHECKSUMS}" || err "checksums download failed"
+
+# Verify
+msg "Verifying checksum"
+(cd "$TMP" && sha256sum --check --ignore-missing "$CHECKSUMS") || err "checksum verification failed"
+
+# Extract
+msg "Extracting"
+tar -xzf "${TMP}/${TARBALL}" -C "$TMP"
+
+# Install
+msg "Installing to /usr/local/bin (sudo)"
+sudo install -m 0755 "${TMP}/archduino" /usr/local/bin/archduino
+
+msg "Installing shell completions"
+sudo install -Dm 0644 "${TMP}/completions/archduino.bash" /usr/share/bash-completion/completions/archduino
+sudo install -Dm 0644 "${TMP}/completions/_archduino"     /usr/share/zsh/site-functions/_archduino
+sudo install -Dm 0644 "${TMP}/completions/archduino.fish" /usr/share/fish/vendor_completions.d/archduino.fish
+
+msg "Launching: archduino install $*"
+exec /usr/local/bin/archduino install "$@"
+```
+
+- [ ] **Step 2: Make it executable and shellcheck it**
+
+```bash
+chmod +x bootstrap.sh
+command -v shellcheck && shellcheck bootstrap.sh || echo "(shellcheck not installed — skipping)"
+```
+
+Expected: `shellcheck` passes with no warnings. If warnings appear, fix them (common ones: quote expansions, etc.).
+
+- [ ] **Step 3: Smoke-test the non-root path in a container**
+
+This step requires a snapshot tarball. Skip if Docker is unavailable — the workflow will validate end-to-end.
+
+```bash
+make snapshot
+# Serve dist/ locally
+(cd dist && python3 -m http.server 8000 &) ; SERVER_PID=$!
+sleep 1
+# In a throwaway Arch container, verify the prereq + download logic.
+# Since Gitea API isn't reachable in the container, we only eyeball the
+# script behavior up to the API call:
+docker run --rm -v "$PWD/bootstrap.sh:/bootstrap.sh:ro" archlinux bash -c \
+  'head -40 /bootstrap.sh && echo "--- script is syntactically valid shell ---" && bash -n /bootstrap.sh'
+kill $SERVER_PID 2>/dev/null || true
+```
+
+Expected: `bash -n` reports no syntax errors. (Full e2e test is gated on Task 8.)
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add bootstrap.sh
+git commit -m "feat: add bootstrap.sh curl-piped installer"
+```
+
+---
+
+## Task 6: .gitea/workflows/release.yml
+
+**Files:**
+- Create: `.gitea/workflows/release.yml`
+
+- [ ] **Step 1: Write the workflow**
+
+Create `.gitea/workflows/release.yml`:
+
+```yaml
+name: release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Run goreleaser
+        uses: goreleaser/goreleaser-action@v6
+        with:
+          distribution: goreleaser
+          version: '~> v2'
+          args: release --clean
+        env:
+          GITEA_TOKEN: ${{ secrets.RELEASE_TOKEN }}
+```
+
+- [ ] **Step 2: Lint the YAML**
+
+```bash
+command -v yamllint && yamllint .gitea/workflows/release.yml || python3 -c "import yaml,sys; yaml.safe_load(open('.gitea/workflows/release.yml'))" && echo "yaml ok"
+```
+
+Expected: no errors.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add .gitea/workflows/release.yml
+git commit -m "ci: add Gitea Actions release workflow"
+```
+
+---
+
+## Task 7: Retire install.sh and update README
+
+**Files:**
+- Rename: `install.sh` → `install.sh.legacy`
+- Modify: `README.md`
+
+- [ ] **Step 1: Rename install.sh**
+
+```bash
+git mv install.sh install.sh.legacy
+```
+
+Add a one-line header to the top of `install.sh.legacy` explaining the rename. Use Edit with these exact lines (the first original line is `#!/bin/bash` or similar — verify and preserve):
+
+Read the first 3 lines first to know exact content:
+```bash
+head -3 install.sh.legacy
+```
+
+Then use Edit to prepend:
+```bash
+# DEPRECATED: This is the legacy Bash installer. The active installer is
+# bootstrap.sh (curl-piped shim) + the archduino Go binary. Kept for reference.
+```
+
+Inserted as the second line (below the shebang).
+
+- [ ] **Step 2: Update README install section**
+
+Read the current install section:
+```bash
+grep -n -A 20 -i "install" README.md | head -40
+```
+
+Replace whatever install instructions currently exist with a block that contains:
+
+```markdown
+## Installation
+
+One-line install on Arch Linux:
+
+```bash
+curl -fsSL https://gitlab.hive-brain.de/MDietermann/Archduino/raw/branch/master/bootstrap.sh | bash
+```
+
+This fetches the latest release, verifies its checksum, installs `archduino`
+to `/usr/local/bin`, installs shell completions, and launches
+`archduino install`.
+
+### Development
+
+Local build:
+
+```bash
+make build
+./archduino --help
+```
+
+Releasing (maintainers only):
+
+```bash
+go install github.com/caarlos0/svu@latest
+make release   # prompts with computed next version, tags, pushes
+```
+```
+
+Use Edit to splice this in at the appropriate location. If the README has no install section, append it after the title/intro.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add install.sh.legacy README.md
+git rm install.sh 2>/dev/null || true  # git mv already handles this
+git commit -m "docs: update README for bootstrap.sh install; retire install.sh"
+```
+
+---
+
+## Task 8: End-to-end snapshot verification
+
+**Files:** none (validation only)
+
+- [ ] **Step 1: Clean snapshot**
+
+```bash
+make clean
+make snapshot
+ls dist/
+```
+
+Expected: `checksums.txt`, two `.tar.gz` archives, build dirs.
+
+- [ ] **Step 2: Verify tarball contents match bootstrap.sh expectations**
+
+```bash
+tar -tzf dist/archduino_*_linux_amd64.tar.gz | sort
+```
+
+Expected (order may vary):
+```
+LICENSE
+README.md
+archduino
+completions/_archduino
+completions/archduino.bash
+completions/archduino.fish
+```
+
+The paths must match what `bootstrap.sh` extracts and installs. If the archive layout differs (e.g. everything under a top-level dir), adjust `.goreleaser.yaml` `archives.wrap_in_directory: false` or update `bootstrap.sh`'s install paths.
+
+- [ ] **Step 3: Verify checksums file format**
+
+```bash
+cat dist/checksums.txt
+```
+
+Expected: one line per archive, `<sha256>  archduino_<version>_linux_<arch>.tar.gz`. This is what `sha256sum --check` consumes.
+
+- [ ] **Step 4: Bash-syntax-check bootstrap.sh against a snapshot in a container**
+
+```bash
+docker run --rm -v "$PWD:/work:ro" archlinux bash -c '
+  set -e
+  pacman -Sy --needed --noconfirm bash curl >/dev/null
+  bash -n /work/bootstrap.sh
+  echo "syntax ok"
+'
+```
+
+Expected: `syntax ok`. (Full network-dependent e2e is gated on the first real release.)
+
+- [ ] **Step 5: Commit nothing; verification is informational**
+
+No commit. If any step failed, go back to the relevant task and fix.
+
+---
+
+## Task 9: Register Gitea Actions runner and first release
+
+**Files:** none (operational)
+
+This task is operational, performed once. Coordinate with the user before executing.
+
+- [ ] **Step 1: Confirm with the user**
+
+Before running any of the steps below, confirm with the user that they want to proceed with a real release. Gitea Actions runner registration and the first tag are both irreversible-ish actions that affect the remote repo.
+
+- [ ] **Step 2: Register a Gitea Actions runner**
+
+Runner registration is a one-time step and is performed on a host the user controls (likely the Gitea server or a persistent machine). High-level steps (user runs these — agent does not execute on remote hosts):
+
+1. In Gitea UI → Repo Settings → Actions → Runners → generate a registration token.
+2. On the runner host, install `act_runner` (https://gitea.com/gitea/act_runner).
+3. `act_runner register --instance https://gitlab.hive-brain.de --token <TOKEN>`.
+4. `act_runner daemon &` (or set up a systemd unit).
+
+Verify in the Gitea UI that the runner shows as online.
+
+- [ ] **Step 3: Create a repo-scoped release token**
+
+1. Gitea UI → User Settings → Applications → Generate Token.
+2. Scope: `write:repository` (and `write:package` if future-proofing).
+3. Copy the token.
+4. Repo → Settings → Actions → Secrets → New secret named `RELEASE_TOKEN`, paste the token value.
+
+- [ ] **Step 4: Seed the first tag**
+
+```bash
+# Confirm branch/working-tree
+git checkout master
+git pull
+git status
+# Seed v0.1.0 manually so svu has a baseline
+git tag v0.1.0
+git push origin v0.1.0
+```
+
+Watch the Gitea Actions tab — the `release` workflow should pick up the tag and run goreleaser. Expected outcome: a new Release page at `https://gitlab.hive-brain.de/MDietermann/Archduino/releases/tag/v0.1.0` with two tarballs and `checksums.txt` attached.
+
+- [ ] **Step 5: Smoke-test bootstrap.sh against the real release**
+
+In a throwaway Arch container:
+
+```bash
+docker run --rm -it archlinux bash -c '
+  pacman -Sy --noconfirm curl >/dev/null
+  curl -fsSL https://gitlab.hive-brain.de/MDietermann/Archduino/raw/branch/master/bootstrap.sh | bash -s -- --dry-run
+'
+```
+
+Expected: prereqs install, release detected, tarball downloaded, checksum verified, `archduino install --dry-run` runs and exits cleanly.
+
+- [ ] **Step 6: Merge to master**
+
+Once the first real release is verified, merge the worktree branch back to `master`:
+
+```bash
+git checkout master
+git merge --no-ff feat/plan4c-release
+git push origin master
+```
+
+(Branch name may differ — use whichever worktree was created.)
+
+---
+
+## Notes for the executing agent
+
+- **No Go-side tests** are created in this plan. The deliverables are configs, scripts, and a CI workflow — validation is via `goreleaser check`, `make snapshot`, `bash -n`, and `shellcheck`.
+- **Conventional Commits are required from here on.** `svu` and the goreleaser changelog both depend on them. Commit messages in this plan use that format as a model.
+- **Do not run `make release` during implementation** — it creates real git tags that would pollute the release history. The first real release happens in Task 9 after user confirmation.
+- **If Task 3 snapshot fails** because `completion` isn't registered, revisit Task 1 Step 2 — cobra may have had its default subcommand disabled.
+- **If Task 8 reveals archive layout mismatches**, the fix is in `.goreleaser.yaml` (files stanza or `wrap_in_directory`) rather than `bootstrap.sh`, because goreleaser's layout is the source of truth.

docs/superpowers/specs/2026-04-13-installer-architecture-design.md

@@ -0,0 +1,228 @@
+# Installer Architecture Redesign
+
+**Status:** Design approved, pending implementation plan
+**Date:** 2026-04-13
+**Scope:** Installer architecture only. Toolset overhaul, CLI browser, and TTY-font story are queued as follow-up specs.
+
+## Context
+
+The current Archduino installer is a Bash entry point (`install.sh`) that sources 13 files under `lib/`. It has grown beyond what Bash handles comfortably:
+
+- **Monolithic / ordering-fragile.** `install.sh` sources lib files in a fixed order at top level; hard to run a single step and hard to re-run safely.
+- **Not idempotent / no resume.** Re-running either duplicates work or silently skips things.
+- **Mixed concerns per file.** Detection, templating, package install, and theme application are intertwined in every lib.
+- **Thin UX.** Only choices are theme + verbose; no dry-run, no module selection, no preview.
+- **Platform coupling.** Arch vs Ubuntu-WSL branches are scattered throughout.
+
+The goal is a principled rebuild across all five axes.
+
+## Decision summary
+
+| Area | Choice |
+|---|---|
+| Language / runtime | Go, single static binary |
+| UI | Bubble Tea + Huh (wizard for input, dashboard for execution) |
+| Pre-install shim | Minimal Bash script: ensures `sudo`, `git`, `curl`, `ca-certificates`, fetches binary |
+| Module contract | Four-phase: `Detect → Plan → Apply → Verify` |
+| Configuration | Embedded defaults + optional `~/.config/archduino/overlay.yaml` |
+| Privilege model | User-mode binary; `sudo` per privileged command; upfront `sudo -v` + keepalive goroutine |
+| State / logging | `Detect()` is authoritative; run log is advisory UX only |
+| Failure policy | DAG execution; failed node fails its descendants; siblings proceed; `--halt-on-error` flag available |
+| Subcommands | One binary: `install`, `theme`, `new`, `doctor` |
+| Platform scope (v1) | Arch-only native + WSL2; `PackageManager` interface ready for Debian/Fedora later |
+
+## Architecture
+
+### Module contract
+
+Every installable unit implements:
+
+```go
+type Module interface {
+    Meta() ModuleMeta                       // id, human name, description, deps []string
+    Detect(ctx) (State, error)              // read current system
+    Plan(ctx, State) (Plan, error)          // diff vs desired; []Action with descriptions
+    Apply(ctx, Plan, *Reporter) error       // execute; stream progress to Reporter
+    Verify(ctx) error                       // confirm desired state reached
+}
+```
+
+- `State` is module-defined.
+- `Plan` is a flat list of `Action{Description, Kind, Exec}` so the engine can render plans without knowing modules.
+- `Reporter` decouples modules from the TUI.
+- **`Detect()` is authoritative.** No cached state overrides what the system reports.
+
+Initial module set (1:1 with today's `lib/*.sh`):
+`packages`, `fonts`, `zsh`, `starship`, `zellij`, `neovim`, `yazi`, `arduino-cli`, `renode`, `git` (lazygit), `scaffold`, `shell-config`, `themes`.
+
+### Execution engine
+
+- **DAG-scheduled.** Modules declare `deps []string`. Engine topologically sorts and runs independent branches concurrently, default parallelism 4.
+- **Failure policy.** Failed node marks its descendants `skipped-due-to-dep`; siblings proceed. End-of-run summary: `X succeeded, Y failed, Z skipped`.
+- **Dry-run** (`--dry-run`, or wizard "Review plan" step): runs Detect + Plan for every selected module, renders the combined plan, exits.
+- **Halt mode** (`--halt-on-error`): opts into fail-fast for scripted use.
+- **Resume hint.** If a prior run log exists, TUI offers "last run: `starship` failed — resume? / start over? / pick modules?" Hint only; Detect decides what actually runs.
+
+### Configuration
+
+- **Embedded defaults** via `//go:embed`: package lists, theme files, Zellij layouts, config templates.
+- **Optional overlay** at `~/.config/archduino/overlay.yaml`:
+  ```yaml
+  version: 1
+  extra_packages: [htop, ncdu]
+  disabled_modules: [renode]
+  theme_overrides:
+    starship: ~/my-starship.toml
+  ```
+- Overlay is merged at load time. Schema is versioned; a migration path exists when it grows.
+
+### Privilege model
+
+- Binary runs as the invoking user.
+- On `install` start, one `sudo -v` call; a keepalive goroutine refreshes the timestamp every 50 seconds while the installer is live.
+- Privileged operations shell out to `sudo pacman …`, `sudo usermod …`. If sudo needs to re-prompt (timestamp expired), the TUI is suspended via `tea.ExecProcess`.
+- Config files, git clones, and anything under `$HOME` run as the user — no root-owned files in home.
+
+### Platform abstraction
+
+```go
+type PackageManager interface {
+    Install(pkgs []string) error
+    IsInstalled(pkg string) (bool, error)
+    Update() error
+    Name() string
+}
+```
+
+- V1 ships `Pacman` only. Debian/Ubuntu/Fedora impls are stubbed; wiring them is a later spec.
+- `Platform{Distro, IsWSL, Arch}` detection is centralized. WSL path sets `/etc/wsl.conf` hints and adds the user to `dialout`/`uucp`.
+
+### State and logs
+
+- `~/.local/state/archduino/runs/<timestamp>.json` — per-run structured log: `{module, phase, status, duration, error}`.
+- `~/.local/state/archduino/last.json` — most recent run; read by TUI for the resume hint.
+- Log rotation: keep the last 10 runs.
+- Safe to delete at any time; never read for correctness decisions.
+
+## User-facing surface
+
+### Pre-install shim (`scripts/bootstrap.sh`)
+
+~30 lines of Bash, served from a stable URL. Invocation:
+
+```bash
+curl -fsSL https://archduino.dev/install.sh | bash
+```
+
+Responsibilities in order:
+
+1. Refuse to run as root.
+2. Detect distro; abort with a clear message if not Arch (v1 scope).
+3. Ensure `sudo`, `git`, `curl`, `ca-certificates` are installed (`pacman -S --needed`).
+4. Detect architecture, fetch the matching release binary from GitHub Releases, verify its SHA256 against the published checksum file, install to `~/.local/bin/archduino`, `chmod +x`.
+5. `exec archduino install`.
+
+Everything further (base-devel, multilib, user groups, toolset) is handled by modules inside the binary.
+
+### Subcommands
+
+| Command | Purpose |
+|---|---|
+| `archduino install` | Default; wizard + dashboard flow |
+| `archduino theme [name]` | Switch colorscheme across all tools; no arg = TUI picker |
+| `archduino new <name> <board>` | Scaffold a project (current `arduino-new` behavior) |
+| `archduino doctor` | Run Detect across all modules; report drift in a read-only dashboard |
+| `archduino --version` / `completion <shell>` | Standard |
+
+Global flags: `--dry-run`, `--halt-on-error`, `--verbose`, `--no-tui`, `--only <mods>`, `--skip <mods>`.
+
+Shell aliases `theme` and `arduino-new` are preserved via thin wrappers dropped in `~/.local/bin` by the `shell-config` module.
+
+### TUI flow (`install`)
+
+**Wizard phase (Huh forms):**
+
+1. Welcome — detected platform, WSL status, binary version.
+2. Theme picker — 5 options, palette preview.
+3. Module selector — checkbox list; pre-ticked from overlay or "all" by default; disabled modules grayed with reason.
+4. Advanced (collapsible) — parallelism, halt-on-error toggle, overlay path override.
+5. Review plan — rendered `Plan()` grouped by module, expandable. Back-navigable.
+6. Confirm — `[y/N]` gate into Apply.
+
+**Apply phase (Bubble Tea dashboard):**
+
+```
+┌─ archduino install ──────────────────────────────────┐
+│ ✓ packages          12/12   2.4s                     │
+│ ✓ fonts              1/1    0.8s                     │
+│ ⠋ neovim             3/7    running: :MasonInstall…  │
+│ ⠋ arduino-cli        2/4    running: core install…   │
+│ · zellij             pending (waits: packages)       │
+│ ✗ starship           failed — config template parse  │
+│ ⊘ shell-config       skipped (dep: starship)         │
+├──────────────────────────────────────────────────────┤
+│ [tab] focus module  [enter] expand log  [q] abort    │
+└──────────────────────────────────────────────────────┘
+```
+
+- Concurrent modules visible live.
+- `enter` on a row expands a scrollable log tail.
+- On completion: summary view; footer offers `[r]etry failed / [v]iew full log / [q]uit`.
+
+## Project layout
+
+```
+archduino/
+├── cmd/archduino/          # main.go, cobra wiring
+├── internal/
+│   ├── engine/             # DAG scheduler, Reporter, dry-run, resume
+│   ├── module/             # Module interface, Plan/Action types, registry
+│   ├── modules/            # one package per module
+│   │   ├── packages/
+│   │   ├── zsh/
+│   │   └── ...
+│   ├── platform/           # detection; PackageManager interface + pacman impl
+│   ├── privilege/          # sudo -v + keepalive
+│   ├── config/             # embedded defaults + overlay merge
+│   ├── state/              # run log, last-run tracking
+│   ├── theme/              # theme model + switcher
+│   └── tui/
+│       ├── wizard/         # Huh forms
+│       └── dashboard/      # Bubble Tea Apply view
+├── assets/                 # embedded configs, themes, zellij layout, templates
+│   ├── themes/
+│   ├── templates/
+│   └── layouts/
+├── scripts/bootstrap.sh
+├── .github/workflows/
+│   ├── ci.yml
+│   └── release.yml         # goreleaser
+└── docs/
+```
+
+## Testing
+
+- **Unit** — every module's `Detect` and `Plan` against an injected `System` fake; table-driven cases for clean / already-installed / partial / drifted.
+- **Engine** — DAG scheduling, failure propagation, dry-run, resume; pure Go, fully covered.
+- **Integration** — Dockerfile on `archlinux:base` runs `archduino install --no-tui --yes` end-to-end in CI; asserts key files/packages/services. One matrix entry for native Arch. WSL smoke test remains manual for v1.
+- **TUI** — `teatest` for wizard navigation and dashboard state transitions. No screenshot tests.
+
+## Distribution
+
+- **GitHub Releases** via `goreleaser`: `linux/amd64`, `linux/arm64` static binaries; `SHA256SUMS` file.
+- No AUR package for v1; the shim is the distribution channel. AUR can follow later.
+- Semver; breaking changes bump major.
+
+## Migration
+
+- Existing `install.sh` + `lib/*.sh` stay on `master` at a tagged `v0-bash-final` so users can still run the old installer if they want.
+- `feat/renode-dap` merges first; a new `feat/go-rewrite` branch hosts the rewrite.
+- First Go release (`v1.0.0`) lands when feature parity with the current Bash installer is verified on a clean Arch VM.
+
+## Out of scope (queued for follow-up specs)
+
+- Toolset redesign (re-evaluating which CLI tools are curated).
+- CLI browser integration.
+- Nerd Font rendering on bare TTY (constrained by the Linux console's 512-glyph PSF limit; needs a separate design covering `fbterm`/`kmscon` or the "SSH-in-from-a-real-terminal" fallback).
+- Non-Arch platform support (Debian/Ubuntu/Fedora).
+- AUR packaging.

docs/superpowers/specs/2026-04-14-ci-workflow-design.md

@@ -0,0 +1,99 @@
+# CI Workflow Design (Plan 4d)
+
+**Date:** 2026-04-14
+**Scope:** Plan 4d of the Archduino Go rewrite — validate Go code quality, build health, and release config on every change.
+
+## Goal
+
+A single Gitea Actions workflow that gives fast, reliable feedback on every push and pull request. It runs unit tests with the race detector, static checks, a build sanity pass, shell-script linting, and validates the goreleaser config — all inside an Arch Linux container for environmental fidelity with the target platform.
+
+## Non-goals
+
+- No integration tests that invoke a real `archduino install` against live pacman/AUR mirrors. That requires a privileged container and mirror access; it lives in a future plan if ever needed.
+- No `golangci-lint`. The `go vet` + `gofmt` baseline is enough for this codebase; revisit only if linting gaps surface.
+- No coverage reporting or codecov upload.
+- No scheduled/nightly runs. Trigger is push + PR only.
+
+## Trigger
+
+```yaml
+on:
+  push:
+  pull_request:
+```
+
+Fires on every push to every branch and every pull request. Matches a single-developer workflow where noisy branches aren't a real concern; immediate feedback is worth the runner minutes.
+
+## Runner
+
+- `runs-on: ubuntu-latest` — same runner label used by the Plan 4c release workflow.
+- `container: archlinux:latest` — tests execute inside a fresh Arch userspace each run, matching Archduino's sole supported OS.
+
+**Runner infrastructure:** depends on the same Gitea Actions runner registered for Plan 4c. No new infra introduced by this plan. If the runner is offline, CI queues rather than failing; this is acceptable behavior.
+
+## Job steps (single job, sequential)
+
+1. **Install container prereqs.** Before `actions/checkout` can run, the Arch image needs git; the later steps also need `base-devel` (for the C toolchain Go occasionally pulls in for cgo-adjacent deps) and `shellcheck`. Run once up front:
+   ```
+   pacman -Sy --needed --noconfirm base-devel git shellcheck
+   ```
+   Note: `go` is intentionally NOT installed here — `actions/setup-go` installs the pinned version.
+
+2. **Checkout code.** `actions/checkout@v4` with `fetch-depth: 1` (CI doesn't need history).
+
+3. **Set up Go.** `actions/setup-go@v5` with:
+   - `go-version-file: go.mod` (pinned, deterministic)
+   - `cache: true` (built-in cache of `$GOMODCACHE` + `$GOCACHE`, keyed on `go.sum`)
+
+4. **`go vet ./...`** — catches obvious correctness issues the compiler misses.
+
+5. **`gofmt` check:**
+   ```
+   diff=$(gofmt -l .)
+   if [ -n "$diff" ]; then
+     echo "files need gofmt:"; echo "$diff"; exit 1
+   fi
+   ```
+   Fails the build if any Go file isn't canonically formatted.
+
+6. **`go build ./...`** — compiles every package. Catches deadcode paths and untested packages that `go test` would otherwise skip.
+
+7. **`go test -race ./...`** — full unit test suite with the race detector. The engine (DAG scheduler) and `privilege.Acquire` (sudo keepalive goroutine) are the concurrency hotspots this covers.
+
+8. **`shellcheck bootstrap.sh`** — lints the user-facing shell installer. `install.sh.legacy` is NOT linted; it's archived code.
+
+9. **Install goreleaser + `goreleaser check`:**
+   ```
+   go install github.com/goreleaser/goreleaser/v2@latest
+   "$(go env GOPATH)/bin/goreleaser" check
+   ```
+   Validates `.goreleaser.yaml` on every change. Cheap insurance against config drift.
+
+## Runtime expectations
+
+- Arch image pull: ~15–30s (cached on the runner after first run).
+- `pacman -Sy … base-devel git shellcheck`: ~10–20s.
+- `actions/setup-go` + cache restore: ~5–10s warm, ~30s cold.
+- `go build ./...` + `go test -race ./...`: ~30–60s given 37 test files with mostly mocked I/O.
+- `go vet`, `gofmt`, `shellcheck`, `goreleaser check`: <5s combined.
+- **Total per run:** ~1–2 min warm cache, ~3 min cold.
+
+## Error handling
+
+- Sequential steps; the first failure fails the workflow. No `continue-on-error` anywhere.
+- `gofmt` check uses an explicit guard (not just `-l`) so a non-empty output is a clear failure.
+- `setup-go` cache misses silently fall back to a clean install — no workflow-breaking behavior.
+
+## Caching
+
+`actions/setup-go@v5` handles Go build/module caching natively via `cache: true`. No extra cache step. The `pacman` packages are re-installed every run; caching them is not worth the complexity for ~15s of savings on a 90s run.
+
+## Files touched
+
+- Create: `.gitea/workflows/ci.yml`
+
+No other repo changes; the existing tests, `go.mod`, `.goreleaser.yaml`, and `bootstrap.sh` all stay as-is.
+
+## Interaction with Plan 4c
+
+The release workflow (`.gitea/workflows/release.yml`) is unchanged. Both workflows share the Gitea Actions runner but never run together: CI fires on push/PR, release fires on tag push. Independent files, independent triggers, zero coupling.

docs/superpowers/specs/2026-04-14-force-reapply-design.md

@@ -0,0 +1,161 @@
+# Force Reapply Design (Plan 4b)
+
+**Date:** 2026-04-14
+**Scope:** Plan 4b of the Archduino Go rewrite — add `archduino install --force` that re-runs every selected module's Apply unconditionally.
+
+## Goal
+
+Let the user bypass the four-phase contract's idempotency guard when they explicitly want to reapply everything — typically after a manual edit, corruption, or "I'm not sure what's broken, redo it" scenario. Scope is narrow: force a full reapply of currently-selected modules. No uninstall, no revert, no selective force-by-category.
+
+## Non-goals
+
+- No uninstall / reset / revert behavior. Modules have no `Revert` method today; adding one is a separate, much larger plan.
+- No selective force (`--force-configs`, `--force-packages`). The user picked "full re-everything" during brainstorming; single flag only.
+- No new subcommand (`archduino reinstall`). A flag on `install` is enough.
+- No changes to `Verify`; force affects only what `Apply` does, not how we confirm it.
+
+## Interface change
+
+Add one method to `module.Module`:
+
+```go
+// PlanForce returns a plan that reapplies the module unconditionally,
+// ignoring current detected state. Used by `archduino install --force`.
+// Implementations should produce a plan equivalent to "install from
+// scratch" — reinstall all packages (without pacman's --needed guard)
+// and rewrite all managed config files.
+PlanForce(ctx context.Context) (Plan, error)
+```
+
+Every existing module implements this. Two categories:
+
+### Config-writing modules
+`zsh`, `neovim`, `themes`, `starship`, `shellconfig`, `zellij`, `yazi` (config bits), `arduinocli` (sketch dirs, indexes).
+
+`PlanForce` produces a plan that:
+1. Reinstalls packages via `platform.Pacman.Reinstall` / `platform.Yay.Reinstall` (no `--needed`).
+2. Rewrites every managed config file, overwriting existing content.
+3. Re-runs any post-install steps (e.g., arduino-cli core update, zsh plugin clone).
+
+### Package-only modules
+`packages`, `gittools`, `fonts`, `renode`, and the package-only portions of `starship` / `yazi`.
+
+`PlanForce` produces a plan that calls `platform.Pacman.Reinstall(ctx, pkgs)` — identical to the install step but without `--needed`, so pacman physically re-fetches and reinstalls the package even if already present.
+
+## Platform layer additions
+
+`internal/platform/pacman.go`:
+```go
+// Reinstall runs `pacman -S --noconfirm pkg...` without the --needed flag
+// so pacman unconditionally reinstalls each package.
+func (p Pacman) Reinstall(ctx context.Context, pkgs []string) error
+```
+
+`internal/platform/aur.go`:
+```go
+// Reinstall runs `yay -S --noconfirm pkg...` without the --needed flag.
+func (y Yay) Reinstall(ctx context.Context, pkgs []string) error
+```
+
+Both are straight copies of the existing `Install` methods with `--needed` omitted from the command-line args.
+
+## Engine changes
+
+`internal/engine/engine.go`:
+
+- `RunOptions` gains a field:
+  ```go
+  Force bool
+  ```
+- `Run` per-module path becomes:
+  ```go
+  var plan module.Plan
+  if opts.Force {
+      plan, err = mod.PlanForce(ctx)
+  } else {
+      cur, derr := mod.Detect(ctx)
+      if derr != nil { /* existing error handling */ }
+      plan, err = mod.Plan(ctx, cur)
+  }
+  ```
+  When `Force` is true, `Detect` is not called.
+
+The Apply and Verify phases are unchanged. Force does not affect DAG ordering, reporter output, or halt-on-error behavior.
+
+## CLI changes
+
+`cmd/archduino/main.go::newInstallCmd()`:
+
+```go
+var force bool
+cmd.Flags().BoolVar(&force, "force", false,
+    "Reapply every selected module, ignoring current state")
+```
+
+In `RunE`, propagate to both engine and wizard:
+```go
+runOpts.Force = force
+initialState.Force = force
+```
+
+## Wizard / TUI integration
+
+`internal/tui/state.go` — `WizardState` gains:
+```go
+Force bool
+```
+
+`internal/tui/wizard/wizard.go` — the `planCache` path branches:
+- When `state.Force` is true, call `PlanForce(ctx)` instead of `Detect` + `Plan`.
+- When a user toggles a module's selection, the cache key includes `force` so caches from non-force runs are not reused.
+- Header gains a persistent banner: `⚠ Force mode: all selected modules will be reapplied`.
+
+## Data flow
+
+```
+user: archduino install --force
+  → main.go: force=true → RunOptions.Force = true, WizardState.Force = true
+  → wizard.Run: per-module preview uses PlanForce (skips Detect)
+  → user confirms
+  → engine.Run: per-module PlanForce → Apply → Verify
+```
+
+## Error handling
+
+No new failure modes. `PlanForce` errors are handled identically to `Plan` errors: reported via the reporter, counted in the engine summary, respected by `--halt-on-error`.
+
+## Testing
+
+**Per-module tests** — each existing `*_test.go` gains a `TestPlanForce` case. The test arranges a "satisfied" system state (mocked platform says everything is installed, configs exist), calls `PlanForce(ctx)`, and asserts the returned plan is non-empty and contains the expected reinstall/rewrite actions. This is the core behavioral contract — without this test, a module could silently "forget" to implement force.
+
+**Engine test** — `engine_test.go` gets a case using a fake module that records whether `Detect`, `Plan`, and `PlanForce` were called. Runs with `RunOptions.Force: true` and asserts `Detect` was NOT called and `PlanForce` WAS.
+
+**Platform tests** — `pacman_test.go` and `aur_test.go` each gain a `TestReinstall` that verifies the command-line args include `-S` and `--noconfirm` but do NOT include `--needed`.
+
+**No TUI test for the banner** — visual-only, covered by the existing wizard tests for preview-cache behavior which will get a new "force preview" case.
+
+## Interaction with existing features
+
+- `--dry-run --force` prints the force plan and exits. Existing dry-run code path is unchanged.
+- `--only`/`--skip` respect force: force applies only to the selected set.
+- `--halt-on-error` respects force identically.
+- Theme application at end of install (Plan 4a feature) runs unchanged; force doesn't skip it.
+
+## File touch list
+
+**Modified:**
+- `internal/module/module.go` — add `PlanForce` to `Module` interface
+- `internal/engine/engine.go` — add `RunOptions.Force`, branch in `Run`
+- `internal/engine/engine_test.go` — new force test
+- `internal/tui/state.go` — add `WizardState.Force`
+- `internal/tui/wizard/wizard.go` — force-aware preview cache + banner
+- `internal/tui/wizard/wizard_test.go` — new preview test with force
+- `internal/platform/pacman.go` — add `Reinstall` method
+- `internal/platform/pacman_test.go` — new test
+- `internal/platform/aur.go` — add `Reinstall` method
+- `internal/platform/aur_test.go` — new test
+- `cmd/archduino/main.go` — add `--force` flag, wire through
+- 13 module files (`internal/modules/*/*.go`) — implement `PlanForce`
+- 13 module test files — `TestPlanForce` each
+
+**New:** none.

docs/superpowers/specs/2026-04-14-plan3a-install-modules-design.md

@@ -0,0 +1,138 @@
+# Plan 3a — Install Modules (Simple/Medium Tier) Design
+
+**Status:** Approved 2026-04-14
+**Scope:** Port 10 of the 13 Bash install modules to Go. Plan 3b (neovim, renode, scaffold) is a separate brainstorm.
+
+## Goal
+
+Port the 10 simple/medium `lib/*.sh` installer modules into Go packages under `internal/modules/`, each implementing the `module.Module` contract (Detect / Plan / Apply / Verify). Every module is unit-tested against an injected fake `platform.Runner`. Along the way, add the platform helpers these modules need (AUR, download, extract, git-clone, text-block writer) and fix the wizard `renderPlan` UI-blocking watchpoint flagged at the end of Plan 2.
+
+## Architecture
+
+Foundation tasks land first, then modules in simplest-first order:
+
+1. **Wizard cache fix** — cache Detect+Plan results per module; invalidate on selection toggle. One small change, but it unblocks every downstream module from stalling the UI.
+2. **Platform helpers** — `AURHelper` (yay), `Download`, `Extract`, `gitclient`, `textblock`. Each gets its own file, each gets TDD against a fake Runner (except `extract` which uses real tempdirs with fixture archives).
+3. **Ten modules** in this order: packages → gittools(lazygit) → starship → yazi → zsh → fonts → zellij → themes → arduinocli → shellconfig.
+
+All module inputs (package lists, versions, URLs, plugin repos, shell-config blocks) are typed fields on `config.Config` populated from the embedded `defaults.yaml`. Overlay override plumbing already exists from Plan 1. Modules take their inputs as struct fields at construction time — no globals.
+
+## Tech Stack
+
+Go, existing `internal/platform` + `internal/module` + `internal/engine` + `internal/tui` packages. No new external dependencies expected beyond what Plan 1/2 pulled in.
+
+## Files
+
+### New — platform helpers
+
+- `internal/platform/aur.go` + `aur_test.go`
+  - `AURHelper` interface, `Yay` implementation.
+  - `EnsureInstalled(ctx) error` — bootstraps yay from AUR via `git clone https://aur.archlinux.org/yay.git /tmp/... && makepkg -si --noconfirm` when missing.
+  - `Install(ctx, pkgs []string) error` — `yay -S --needed --noconfirm <pkgs...>`.
+  - Takes a `Runner` and a `PackageManager` (to check if `yay` itself is installed).
+
+- `internal/platform/download.go` + `download_test.go`
+  - `Download(ctx, url, destPath string, mode os.FileMode) error`.
+  - Atomic-ish: write to `destPath+".tmp"` then rename. Clean up on error.
+  - Tested with `httptest.Server`.
+
+- `internal/platform/extract.go` + `extract_test.go`
+  - `ExtractTarGz(ctx, archivePath, destDir string) error`.
+  - `ExtractZip(ctx, archivePath, destDir string) error`.
+  - Tested against real fixture archives in `testdata/`.
+
+- `internal/platform/git.go` + `git_test.go`
+  - `GitClient` struct taking a `Runner`.
+  - `Clone(ctx, url, dest string) error`.
+  - `EnsureRepo(ctx, url, dest string) error` — clone if `dest/.git` missing, otherwise noop.
+
+- `internal/platform/textblock.go` + `textblock_test.go`
+  - `EnsureBlock(path, marker, content string) error` — writes or replaces a block delimited by `# >>> marker >>>` / `# <<< marker <<<` markers. Creates the file if missing.
+  - `RemoveBlock(path, marker string) error`.
+  - `HasBlock(path, marker string) (bool, error)`.
+  - Table-driven tests: insert, replace, remove, preserve surrounding content, missing-file, empty-file.
+
+### New — modules
+
+Each lives in its own package under `internal/modules/<name>/` with `<name>.go` + `<name>_test.go`.
+
+- `packages` — installs base pacman package list from `cfg.Packages.Base`.
+- `gittools` — installs lazygit (pacman). Named `gittools` to avoid collision with Go stdlib / pacman `git`.
+- `starship` — installs starship (pacman).
+- `yazi` — installs yazi (pacman).
+- `zsh` — installs zsh (pacman) + clones oh-my-zsh + configured plugins via `gitclient`.
+- `fonts` — installs AUR fonts (e.g. `ttf-jetbrains-mono-nerd`) via `AURHelper`. First action is `EnsureYayInstalled` if needed.
+- `zellij` — installs zellij (pacman) + downloads config.
+- `themes` — copies theme files from source directory (bundled under `lib/themes/` or overridable via `cfg.Themes.Source`).
+- `arduinocli` — downloads arduino-cli tarball, extracts to `~/.local/bin`, runs `arduino-cli core install <cores...>` from `cfg.ArduinoCLI.Cores`.
+- `shellconfig` — writes marker-delimited blocks into `~/.zshrc`, `~/.bashrc`, etc., using `textblock.EnsureBlock`. Blocks defined in `cfg.ShellConfig.Blocks`.
+
+### Modified
+
+- `internal/config/config.go` + `internal/config/defaults.yaml` — add typed fields:
+  - `Packages.Base []string`
+  - `Fonts []string`
+  - `ArduinoCLI{Version string, URL string, Cores []string}`
+  - `Starship{Version string}` (reserved; pacman install doesn't need it but overlay may)
+  - `Zsh{OhMyZshRepo string, Plugins []struct{Name, Repo string}}`
+  - `Zellij{ConfigURL string}`
+  - `Themes{Source string}` (defaults to embedded `lib/themes/`)
+  - `ShellConfig{Blocks []struct{Name, File, Content string}}`
+- `internal/tui/wizard/wizard.go` — cache Detect+Plan per module; invalidate on selection toggle.
+- Module registry (wherever `cmd/archduino/install.go` currently registers `hello`) — register the 10 new modules instead of / alongside `hello`.
+
+## Module Contract Details
+
+All modules follow the same shape:
+
+- **Detect** — pure read. `PackageManager.IsInstalled` per pkg, `os.Stat` per file, `textblock.HasBlock` per marker. Returns a module-private `state` struct. Must be fast (wizard caches results, but Detect still shouldn't shell out more than necessary).
+- **Plan** — given current state, returns `Plan{Actions: []Action}`. Empty actions = already converged (idempotent no-op). No side effects.
+- **Apply** — executes each action sequentially, reporting progress via `Reporter.Progress(id, i, total, description)`.
+- **Verify** — re-runs Detect and asserts convergence. Returns a descriptive error on mismatch.
+
+Error semantics from the engine (`--halt-on-error` flag, sibling-on-failure continuation) apply unchanged.
+
+### Module archetypes
+
+1. **Pacman-only** (packages, gittools, starship, yazi, zellij base, themes deps if any): Detect = `IsInstalled` per pkg; Plan = install missing; Apply = `Pacman.Install`; Verify = all installed.
+2. **AUR** (fonts): same as pacman-only but via `AURHelper`. Plan prepends an `EnsureYay` action if yay is not installed.
+3. **Download + extract** (arduinocli): Detect = probe binary + `--version`; Plan = download + extract + symlink + `arduino-cli core install`; Verify = version string matches.
+4. **Git-clone configs** (zsh oh-my-zsh + plugins, zellij config fetch if URL-based, themes if sourced from repo): Detect = check `.git` or file presence; Plan = `gitclient.EnsureRepo` or `Download`; Verify = path exists.
+5. **Text-block writers** (shellconfig): Detect = `textblock.HasBlock` per block; Plan = `textblock.EnsureBlock`; Verify = re-scan.
+
+## Testing Strategy
+
+**Per-module tests (all unit, all fake-Runner-based):**
+
+1. Detect with nothing installed → absent state.
+2. Detect with everything installed → present state.
+3. Plan(absent) → non-empty actions matching config inputs.
+4. Plan(present) → empty actions (idempotent no-op).
+5. Apply → records correct shell commands against fake Runner.
+6. Verify after Apply → passes when fake reports success.
+
+**Platform helper tests:**
+
+- `aur_test.go` — yay bootstrap path (fake Runner sees `git clone` + `makepkg -si`), install path, already-installed short-circuit.
+- `download_test.go` — `httptest.Server` for happy path + 404 + mid-download error cleanup.
+- `extract_test.go` — real tar/zip fixtures in `testdata/` extracted into `t.TempDir()`.
+- `git_test.go` — fake Runner for clone-if-missing, skip-if-present.
+- `textblock_test.go` — table-driven: insert new, replace existing, remove, preserve surrounding content, missing-file, empty-file.
+
+**Wizard caching test:** assert `Detect` is called once per module regardless of redraw count.
+
+**No integration tests** that touch real pacman, real AUR, or the real network. That's Plan 4 (CI with Arch container). Manual smoke after plan completes.
+
+## Non-Goals
+
+- Plan 3b modules (neovim, renode, scaffold) — separate brainstorm.
+- Subcommands beyond `install` (theme/new/doctor) — Plan 4.
+- `bootstrap.sh`, goreleaser, CI — Plan 4.
+- Debian/Fedora PackageManager implementations — Plan 4+.
+- Integration tests against real package managers — Plan 4.
+
+## Open Risks / Watchpoints
+
+- **AUR bootstrap fragility** — if `makepkg -si --noconfirm` prompts despite `--noconfirm` (sudo password mid-build), the fake-Runner tests won't catch it. Manual smoke on fonts module is essential.
+- **arduino-cli URL drift** — hardcoded version in `defaults.yaml` will go stale. Acceptable for v1; doctor subcommand in Plan 4 can warn.
+- **Theme file source** — if themes ship bundled via Go `embed`, we need to decide that at module time. Default assumption: copy from `lib/themes/` on disk (same behavior as bash); switch to `embed` only if it's a clear win.

docs/superpowers/specs/2026-04-14-plan3b-install-modules-design.md

@@ -0,0 +1,114 @@
+# Plan 3b — Install Modules (Heavy Tier) Design
+
+**Status:** Approved 2026-04-14
+**Scope:** Port 2 of the 3 remaining Bash install modules (`neovim`, `renode`). The third (`scaffold`) is deferred to Plan 4, where its functionality is absorbed natively into the `archduino new` and `archduino theme` subcommands rather than shipped as bash helper scripts.
+
+## Goal
+
+Port the `neovim` and `renode` Bash modules to Go, each implementing the `module.Module` four-phase contract, unit-tested against a fake `platform.Runner`. Add one small platform helper (`WriteUserFile`), extend `config.Config` with the new modules' inputs, extend `tui.Theme` so the wizard's theme selection flows into NvChad's `chadrc.lua`, and register the two modules in the install command.
+
+## Architecture
+
+- **neovim**: pacman-install neovim (Arch ships 0.11.x, no upstream-tarball fallback); clone the NvChad starter to `~/.config/nvim` if no existing config; if a non-NvChad config is detected, back it up to `~/.config/nvim.bak.<RFC3339>` and install fresh (no LazyVim-specific salvage — deliberate scope cut); strip the starter's `nvim-lspconfig` block (we use native `vim.lsp`); render `chadrc.lua` from an embedded template with the selected theme's `NvChadTheme`; write five static Lua asset files (`arduino.lua`, `clangd.lua`, `lspconfig.lua`, `dap.lua`, `mappings.lua`); clear NvChad's base46 theme cache.
+- **renode**: AUR-install `renode-bin` (via `AURHelper`); pacman-install `arm-none-eabi-gdb`; render and write `~/.local/bin/arduino-sim` from an embedded bash template driven by a platform map in config; download `wokwi-cli` from a version-pinned URL into `~/.local/bin/wokwi-cli` (mode 0755).
+- Both modules' artifacts (Lua files, bash helper) live as real files under `internal/modules/<name>/assets/` and are bundled via `go:embed`. No sudo required at runtime; everything lands in user-owned paths.
+- One new platform helper, `platform.WriteUserFile(path, data, mode)`, consolidates the repeated `os.MkdirAll + os.WriteFile` pattern and does an atomic tmp+rename write. Plan 3a modules are not retrofitted — they stay as-is.
+
+## Tech Stack
+
+Go stdlib only for the new helper and modules (`embed`, `text/template`, `os`, `path/filepath`). Relies on all Plan 3a platform helpers (pacman, AUR, download, extract, git) and on `internal/module` / `internal/engine` / `internal/tui` from Plans 1-2.
+
+## Files
+
+### New — platform helper
+
+- `internal/platform/writefile.go` + `writefile_test.go`
+  - `WriteUserFile(path string, data []byte, mode os.FileMode) error`
+  - Creates parent directory (0755) if missing, writes to `path+".tmp"`, renames to `path`.
+  - Tests: happy path (content + mode), missing parent dir (creates it), overwrite preserves atomicity (crash-proof against partial writes is out of scope; atomic rename is sufficient).
+
+### New — modules
+
+- `internal/modules/neovim/neovim.go` + `neovim_test.go` + `assets/`
+  - `assets/chadrc.lua.tmpl` — `text/template` with `{{.NvChadTheme}}`.
+  - `assets/arduino.lua`, `assets/clangd.lua`, `assets/lspconfig.lua`, `assets/dap.lua`, `assets/mappings.lua` — static, copied verbatim from the bash heredocs in `lib/neovim.sh`.
+  - Constructor: `New(cfg config.NeovimConfig, themeID string, themes []tui.Theme, pm platform.PackageManager, git platform.GitClient) Module`.
+  - State: `NvimInstalled, StarterCloned, ChadrcPresent, BackupNeeded bool`, `MissingAssets []string`, `ThemeName string` (resolved at Detect time).
+
+- `internal/modules/renode/renode.go` + `renode_test.go` + `assets/`
+  - `assets/arduino-sim.tmpl` — `text/template` with `{{range .Platforms}}...{{end}}` rendering the case-statement platform map from config.
+  - Constructor: `New(cfg config.RenodeConfig, pm platform.PackageManager, aur platform.AURHelper) Module`.
+  - State: `RenodeInstalled, GdbInstalled, SimScriptCurrent, WokwiInstalled bool`.
+
+### Modified
+
+- `internal/config/config.go` + `internal/config/defaults.yaml`
+  - `type NeovimConfig struct { NvChadStarterRepo string }`
+  - `type RenodePlatform struct { Name, ReplPath, Machine string }`
+  - `type RenodeConfig struct { WokwiVersion, WokwiURL string; Platforms []RenodePlatform }`
+  - `Config` gains `Neovim NeovimConfig` and `Renode RenodeConfig`.
+  - `merge` gains overlay-replace clauses for both (matching Plan 3a's pattern).
+  - `defaults.yaml` populated with NvChad starter URL, pinned wokwi version/URL, and the three platform entries from `lib/renode.sh`.
+
+- `internal/tui` (wherever `BuiltinThemes` is declared — likely `internal/tui/state.go` or a themes file)
+  - `Theme` gains `NvChadTheme string`. Populate for each builtin entry (one-line edits per theme).
+  - Helper `Theme(themes []Theme, id string) (Theme, bool)` for the neovim module to resolve its themeID. (If an equivalent helper already exists, reuse it.)
+
+- `cmd/archduino/main.go` — `buildRegistry` gains a `selectedThemeID string` parameter; registers neovim and renode. TUI path: call `buildRegistry(cfg, tui.DefaultThemeID())` before the wizard, then after the wizard returns with a theme selection, call it again with the selected ID before invoking the dashboard. Plain-output path: pass `cfg`'s default theme directly.
+
+## Module Contract Details
+
+Both modules use the Plan 3a archetype pattern:
+
+- **Detect** — pure reads: `PackageManager.IsInstalled`, `os.Stat`, byte-compare of rendered/static asset files against their destination paths. For neovim, `~/.config/nvim/lua/chadrc.lua` acts as the NvChad-marker; any `lua/` dir without chadrc triggers `BackupNeeded`.
+- **Plan** — emit only missing actions; empty plan = already converged (idempotent).
+- **Apply** — sequential actions with `Reporter.Progress`; no action is retried.
+- **Verify** — re-run Detect; every boolean must be true and `MissingAssets`/related slices must be empty.
+
+Error semantics unchanged from Plan 3a — engine's `--halt-on-error` and sibling-continuation rules apply.
+
+## Theme Propagation
+
+The wizard's `ThemeID` is captured into `tui.WizardState.ThemeID` as before. `buildRegistry` takes the themeID as a second parameter; for the TUI install path, the registry is rebuilt after the wizard confirms selection and before the dashboard runs. For the plain-output path (`--no-tui` / `--dry-run`), the default theme ID is used. The `neovim` module resolves the ID to a `tui.Theme` at construction and stores the `NvChadTheme` for Detect/Plan. If an unknown ID is passed, neovim falls back to the first builtin theme's NvChad name (no hard error — wizards shouldn't crash the installer on a config bug).
+
+## Testing Strategy
+
+### neovim (all unit, tempdir-based)
+
+- `TestDetectFreshSystem` — no nvim, no config → plans pacman install + clone starter + strip lspconfig + write assets.
+- `TestDetectExistingNvChad` — chadrc.lua present → no backup planned; missing-assets test still exercises Plan.
+- `TestDetectNonNvChadTriggersBackup` — `lua/` with no chadrc → `BackupNeeded=true`; Plan includes a rename-to-bak action.
+- `TestPlanApplyInstallsEverything` — fake Runner + fake GitClient + tempdir HOME; asserts pacman call, git clone call, backup done, assets written with expected content, chadrc contains the theme name.
+- `TestPlanAfterApplyIsEmpty` — idempotency.
+- `TestUnknownThemeFallsBackToFirst` — construction with a bogus ID still produces a valid chadrc.
+
+### renode (all unit)
+
+- `TestDetectNothingInstalled` — plans AUR install + pacman install + sim-script write + wokwi download.
+- `TestDetectAllInstalled` — empty plan.
+- `TestApplyWritesSimScript` — rendered script contains each configured platform's case-branch.
+- `TestApplyDownloadsWokwi` — httptest server serves a short payload; verify file written to `~/.local/bin/wokwi-cli` with mode 0755.
+
+### platform.WriteUserFile
+
+- `TestWriteUserFileCreatesParent` — target under a non-existent dir → parent created.
+- `TestWriteUserFileAtomicity` — two sequential writes of different content → final content matches the second; no `.tmp` leaked after success.
+- `TestWriteUserFileErrorCleanup` — a failed write leaves no `.tmp` turd (simulate via read-only parent or unwritable tmp; accept either form if OS makes it awkward).
+
+No integration tests against real pacman, yay, neovim, renode, or GitHub; that's Plan 4's CI.
+
+## Non-Goals
+
+- `scaffold` module — deferred to Plan 4 as native Go subcommands (`archduino new`, `archduino theme`).
+- Upstream Neovim tarball fallback (`/opt/nvim-linux-x86_64`) — pacman is sufficient; version-drift concerns go to Plan 4's `doctor`.
+- LazyVim → NvChad plugin salvage — existing non-NvChad configs get a full backup; user re-adds plugins manually.
+- Wokwi GitHub-API "latest" lookup — version is pinned in config, overrideable via overlay.
+- Retrofitting Plan 3a modules to use `WriteUserFile` — opportunistic cleanup only, not a Plan 3b deliverable.
+- Retroactive theme-sync across every tool (starship, zellij, yazi, lazygit) — Plan 4's `archduino theme` subcommand.
+
+## Open Risks / Watchpoints
+
+- **NvChad starter drift** — if upstream changes `lua/plugins/init.lua`'s `nvim-lspconfig` block format, our sed-equivalent strip-logic in Go will miss it. Mitigation: implement as "find the `{` / `},` block containing the string `neovim/nvim-lspconfig` and delete it", unit-test against a fixture copy of the current starter's `init.lua`.
+- **arduino-sim pinned to Renode's REPL paths** — if Renode renames `platforms/cpus/rp2040.repl`, the sim script breaks. Acceptable for v1; surface via Plan 4 doctor.
+- **Theme propagation race** — rebuilding the registry twice around the wizard is ugly. Alternative considered (module-level `SetTheme` after construction) was rejected as un-idiomatic. Acceptable for 2 modules; revisit if more theme-aware modules appear.
+- **Asset byte-equality idempotency** — if a user edits their `mappings.lua` by hand, every Apply will overwrite it. Documented behavior; `--force-assets` flag is a Plan 4 concern.

docs/superpowers/specs/2026-04-14-plan4a-subcommands-design.md

@@ -0,0 +1,200 @@
+# Plan 4a — User-Facing Subcommands Design
+
+**Status:** Approved 2026-04-14
+**Scope:** Ship three new subcommands — `archduino theme`, `archduino new`, `archduino doctor` — plus the shared `theming` package they all build on. This plan absorbs the functionality of `lib/scaffold.sh` (originally deferred from Plan 3b) and `lib/themes/*.sh` natively into Go, without shipping bash wrappers.
+
+Plan 4b (reinstall/reset mode), 4c (bootstrap + goreleaser), and 4d (CI) are separate plans with independent specs.
+
+## Goal
+
+Complete user-facing feature parity with the Bash installer by adding three subcommands: a theme switcher that updates starship/zellij/yazi/lazygit/NvChad configs in place; a project scaffolder for Arduino sketches; and a doctor command that reports module convergence and pinned-tool version drift.
+
+## Architecture
+
+One new shared package and two subcommand packages:
+
+- **`internal/theming/`** — reusable package that embeds per-theme config assets (5 themes × 4 tool configs + a manifest each) and exposes `List() []Theme`, `Get(id) (Theme, bool)`, and `Apply(cfg, themeID) error`. Called from both the `install` command (applies the wizard's selected theme at the end of an install run) and the new `theme` subcommand.
+- **`internal/subcommands/newproject/`** — owns `archduino new <project> <board>`. Board list lives in `config.Config.Scaffolding.Boards`; `.ino` starter templates embedded.
+- **`internal/subcommands/doctor/`** — owns `archduino doctor`. Iterates the module registry, calls `Detect` + `Plan` on each, reports per-module status and pinned-tool version drift.
+
+`tui.BuiltinThemes` and the `tui.Theme.NvChadTheme` field retire: the canonical theme list is now discovered from `theming`'s embedded manifests. The wizard calls `theming.List()`. `tui.Theme` stays as a thin display value (`ID`, `Name`) used by the wizard's dropdown.
+
+The existing `install` command gains a final step: after `engine.Run` succeeds, call `theming.Apply(cfg, finalState.ThemeID)` so the initial install leaves tools themed, not just installed. This is an improvement over the Bash behavior, where the theme was never applied during install.
+
+## Tech Stack
+
+Go stdlib + existing deps. `go:embed` for all assets. `gopkg.in/yaml.v3` for overlay round-trip updates. `huh` (already a dep) for the interactive theme picker. `text/template` used only where needed (neovim chadrc already uses it; theming's tool configs are static and don't).
+
+## Files
+
+### New — `internal/theming/`
+
+- `theming.go`
+  - Exported: `type Theme struct { ID, DisplayName, NvChadTheme string }`
+  - `func List() []Theme` — returns themes in manifest-discovery order (sort by ID for determinism).
+  - `func Get(id string) (Theme, bool)`
+  - `func Apply(cfg config.Config, themeID string) error`
+  - Private: `discoverThemes()` run once at package init; reads `assets/*/theme.yaml`.
+- `theming_test.go`
+- `assets/<theme>/theme.yaml` — five files (`gruvbox`, `catppuccin`, `tokyonight`, `nord`, `dracula`), each containing:
+  ```yaml
+  display_name: "Gruvbox Dark"
+  nvchad: "gruvbox"
+  ```
+- `assets/<theme>/starship.toml`, `zellij.kdl`, `yazi.toml`, `lazygit.yml` — 20 static config files lifted verbatim from the corresponding `write_*_config` heredocs in `lib/themes/<theme>.sh`. Tool config paths on disk are:
+  - starship.toml → `~/.config/starship.toml`
+  - zellij.kdl → `~/.config/zellij/config.kdl`
+  - yazi.toml → `~/.config/yazi/theme.toml`
+  - lazygit.yml → `~/.config/lazygit/config.yml`
+
+### New — `internal/subcommands/newproject/`
+
+- `newproject.go`
+  - `func Run(cfg config.Config, project, board string) error`.
+- `newproject_test.go`
+- `assets/<board>.ino` — six starter sketches (`uno`, `mega`, `nano`, `esp32`, `esp32s3`, `esp8266`) plus `default.ino`. Content lifted from `lib/scaffold.sh` heredocs.
+
+### New — `internal/subcommands/doctor/`
+
+- `doctor.go`
+  - `func Run(ctx context.Context, cfg config.Config, reg *module.Registry, runner platform.Runner, w io.Writer) (exitCode int)`
+- `doctor_test.go`
+
+### Modified
+
+- `internal/config/config.go` + `internal/config/defaults.yaml`
+  - Add:
+    ```go
+    type Board struct { Name, FQBN, Template string `yaml:"name,fqbn,template"` }
+    type Scaffolding struct { Boards []Board `yaml:"boards"` }
+    ```
+    (adjust tag syntax — yaml tags per field as with existing types).
+  - `Config.Scaffolding Scaffolding`
+  - `merge` clause: `if len(over.Scaffolding.Boards) > 0 { out.Scaffolding = over.Scaffolding }`.
+  - Defaults: the 6 boards from `lib/scaffold.sh` FQBN_MAP with `template` set to the board name (so `template: "uno"` maps to `internal/subcommands/newproject/assets/uno.ino`).
+
+- `internal/modules/neovim/neovim.go`
+  - Extract the chadrc render+write logic into an exported helper the theming package can call. Suggested signature: `func RewriteChadrc(themeID string, themes []Theme) error` (takes themes so the module doesn't depend on the theming package — avoid import cycle). Or simpler: `func WriteChadrc(nvChadThemeName string) error` — takes the already-resolved NvChad name, no theme-registry knowledge needed. The helper no-ops if `~/.config/nvim/lua/chadrc.lua` doesn't exist.
+
+- `internal/tui/state.go`
+  - Remove `BuiltinThemes`, remove `NvChadTheme` field from `Theme`, remove `ThemeByID`. Wizard takes a `[]Theme` parameter or reads from `theming.List()` directly.
+  - Option: delete `tui.Theme` entirely and have the wizard use `theming.Theme` directly. Weigh the import coupling: `internal/tui` already imports `internal/config`, and `theming` imports `config` too, so `tui → theming` is fine.
+
+- `internal/tui/wizard/wizard.go`
+  - Populate the theme dropdown from `theming.List()`.
+
+- `cmd/archduino/main.go`
+  - Add three `cobra.Command` constructors: `newThemeCmd()`, `newProjectCmd()`, `newDoctorCmd()`.
+  - Register them on the root command alongside `install`.
+  - In the `install` RunE, after `engine.Run` returns success, call `theming.Apply(cfg, finalState.ThemeID)` and surface any error.
+  - `buildRegistry` no longer needs to receive `themeID` for neovim's chadrc — neovim's install path writes chadrc based on the ID threaded through `neovim.New`, and `theming.Apply` overwrites it afterward. Keeping the parameter is fine; it remains useful for the initial chadrc write.
+
+## Command surfaces
+
+- `archduino theme` → interactive huh-based picker listing themes; pre-selects `cfg.ThemeOverrides["__active"]` (or the first theme if unset). On confirm, calls `theming.Apply`.
+- `archduino theme <id>` → non-interactive; calls `theming.Apply(cfg, id)`. Errors if unknown.
+- `archduino theme list` → prints `<id> — <display_name>` one per line to stdout.
+- `archduino new <project> <board>` → see data-flow below.
+- `archduino doctor` → see data-flow below.
+
+## Data Flow
+
+### theming.Apply
+
+1. Look up theme by ID; return error if unknown (message lists valid IDs).
+2. For each of the four tool configs under `assets/<theme>/`, read via `embed.FS` and write to its target path via `platform.WriteUserFile` with mode 0o644.
+3. If `~/.config/nvim/lua/chadrc.lua` exists, call `neovim.WriteChadrc(theme.NvChadTheme)` to re-render it. If it doesn't exist, skip silently (user hasn't run install yet, or removed nvim config).
+4. Idempotently clear NvChad's theme cache: `os.RemoveAll(~/.cache/nvim/base46)` and `os.RemoveAll(~/.local/share/nvim/lazy/base46/lua/base46/themes)`. Errors ignored — cache may not exist.
+5. Update the user's overlay file at `~/.config/archduino/overlay.yaml`: load existing YAML (or empty), set `theme_overrides.__active: <id>`, write back via a YAML round-trip using `gopkg.in/yaml.v3` decode-into-map-then-encode. First-run creates the file with the single key.
+
+### newproject.Run
+
+1. Validate `project`: non-empty, no `/` or `\\`, doesn't start with `.`.
+2. Look up board in `cfg.Scaffolding.Boards`. If absent, return an error whose message lists all valid board names, one per line.
+3. `os.Stat(project)`; if it exists, return "project directory already exists". Do not overwrite.
+4. `os.MkdirAll(project, 0o755)`.
+5. Determine `.ino` asset path: `<board.Template>.ino`, falling back to `default.ino` if the board-specific asset is missing. Write to `<project>/<project>.ino` via `platform.WriteUserFile` mode 0o644.
+6. Write `<project>/sketch.yaml`:
+   ```yaml
+   default_fqbn: <FQBN>
+   default_port: auto
+   ```
+7. Write `<project>/.clangd`:
+   ```yaml
+   CompileFlags:
+     Add:
+       - -xc++
+       - -std=c++17
+   ```
+8. Print a success line to stdout: `Created <project>/ (fqbn: <FQBN>). Next: cd <project> && nvim <project>.ino`.
+
+### doctor.Run
+
+1. For each module in `reg.All()`: call `Detect(ctx)`, then `Plan(ctx, state)`. Format output one row per module:
+   - `[✓] <id>` — empty plan (converged).
+   - `[✗] <id> (N actions pending)` — non-empty plan.
+   - `[!] <id> — detect failed: <err>` — Detect/Plan returned error. Never propagate the error up; record and continue.
+2. Version drift checks (only if `arduino-cli` / `wokwi-cli` are found on PATH via the injected `Runner`):
+   - `arduino-cli version --format json` → parse `VersionString`, compare to `cfg.ArduinoCLI.Version`. Print `[✓] arduino-cli <ver>` or `[!] arduino-cli drift: got <X>, want <Y>`.
+   - `wokwi-cli --version` → parse first line's version-like token, compare to `cfg.Renode.WokwiVersion`. Same output format.
+3. Summary line: `<converged>/<total> converged, <pending> need-install, <drift> drift, <errors> errors`.
+4. Exit code: 0 if all modules converged AND no drift AND no errors; else 1. Return value from `Run` is the exit code; the cobra RunE wrapper calls `os.Exit(code)`.
+
+No network calls. No writes. Fast enough to run interactively (<5s on a typical install).
+
+## Error Handling
+
+- `theming.Apply`: first write error aborts. No rollback. User re-runs after fixing (partial state is a benign overlap of two themes' configs on disk until re-run). Overlay update happens last; if a config write fails, the overlay is not touched, so `__active` still reflects the previously-applied theme.
+- `newproject.Run`: refuses to overwrite an existing project directory. All other failures (mkdir, write) bubble up to the cobra layer and print via `RunE`'s default error handling.
+- `doctor.Run`: never returns a Go error. Module failures are reported inline; only a programmer error (e.g., nil registry) would panic.
+
+## Testing
+
+### theming_test.go (all unit, tempdir-based $HOME)
+
+- `TestListReadsManifests` — asserts 5 themes discovered, each with non-empty DisplayName and NvChadTheme.
+- `TestGetKnownAndUnknown` — happy path + false return for bogus ID.
+- `TestApplyWritesAllFourConfigs` — `t.Setenv("HOME", …)`; `Apply(cfg, "dracula")`; assert each of the 4 target files exists with non-empty content and the first line matches the asset's first line (robust to copy-paste drift in tests).
+- `TestApplyUpdatesOverlayActive` — after Apply, `~/.config/archduino/overlay.yaml` contains `theme_overrides.__active: dracula` (round-trip through `gopkg.in/yaml.v3`).
+- `TestApplyPreservesOtherOverlayKeys` — seed overlay with `extra_packages: [foo]`, run Apply, assert `extra_packages` still present after write.
+- `TestApplyRewritesChadrcIfPresent` — seed `~/.config/nvim/lua/chadrc.lua` with gruvbox; Apply dracula; assert file now contains `theme = "dracula"`.
+- `TestApplyNoChadrcIsFine` — no chadrc on disk; Apply succeeds.
+- `TestApplyUnknownThemeErrors`.
+
+### newproject_test.go
+
+- `TestNewCreatesProject` — config with `uno` board; project dir doesn't exist; `Run(cfg, "blinky", "uno")` in a tempdir (chdir); assert `blinky/blinky.ino` + `sketch.yaml` (contains `arduino:avr:uno`) + `.clangd` exist.
+- `TestNewRefusesExistingDir` — pre-create the target dir; `Run` returns error; dir untouched.
+- `TestNewFallsBackToDefaultTemplate` — config board entry whose `.template` points at an asset that doesn't exist (use a made-up board with `template: "xyz"`); Run succeeds and the generated `.ino` matches `default.ino` content.
+- `TestNewUnknownBoardErrors` — error message lists all valid board names.
+- `TestNewRejectsSlashInProjectName`.
+
+### doctor_test.go
+
+- `TestDoctorAllConvergedExitsZero` — single stub module returning empty Plan; runner that makes version commands not-found (`exec: "arduino-cli": executable file not found in $PATH`-style error — skip version checks cleanly). Exit code 0.
+- `TestDoctorDivergedExitsOne` — single stub module returning a Plan with actions; exit code 1.
+- `TestDoctorDetectErrorIsReported` — module whose Detect returns an error; doctor prints `[!]` and exits 1.
+- `TestDoctorArduinoCLIDriftIsReported` — injected Runner returns a different version for `arduino-cli version --format json`; exit code 1; output contains "drift".
+- `TestDoctorMissingBinariesSkipVersionCheck` — runner returns "not found"; no false drift report; exit reflects module status only.
+
+### install-command integration (smoke-level)
+
+- Existing `install` tests continue to pass; add a unit test that stubs `theming.Apply` and asserts `install` calls it after a successful `engine.Run` with the wizard's ThemeID.
+
+No integration tests against real starship/zellij/arduino-cli/wokwi binaries — Plan 4d (CI) introduces those.
+
+## Non-Goals
+
+- Per-user theme creation / custom palettes — pinned to the five built-in themes.
+- Live reload: users must restart their shell, zellij session, etc. manually (bash also required this).
+- `archduino doctor --fix` mode — reserved for a future plan, possibly merged with Plan 4b's reinstall/reset.
+- Version-drift remediation — doctor only reports.
+- `archduino new` support for non-Arduino-CLI ecosystems (PlatformIO, etc.).
+
+## Open Risks / Watchpoints
+
+- **NvChad chadrc extraction:** pulling the render-and-write out of `neovim.Module.Plan`'s closures into a free function requires care — currently that closure is built inside `Plan`. Acceptable fix: factor a `writeChadrc(cfg string, nvChadTheme string) error` free function in the neovim package, have both the Plan action and the new `WriteChadrc` export use it.
+- **tui.Theme retirement:** wizard test coverage is decent but `BuiltinThemes` is referenced in `internal/tui/state_test.go`; removing the symbol requires updating those tests. Grep before deleting.
+- **Overlay YAML round-trip:** `gopkg.in/yaml.v3`'s node-based decoder preserves comments and order; using `map[string]any` decode/encode will lose both. Acceptable for v1 (the user's overlay is config, not hand-commented prose); document the behavior in the `theming.Apply` godoc.
+- **Doctor version parsing:** `arduino-cli version --format json` shape is stable, but `wokwi-cli --version`'s output format is upstream-controlled. A tiny regex `v?\d+\.\d+\.\d+` covers the common case; if it grows fragile, fall back to byte-for-byte compare with `cfg.Renode.WokwiVersion`.
+- **Theme-applied-during-install is a behavior change** vs. Bash. It means a fresh install writes tool configs. If the user had pre-existing starship/zellij configs they liked, they get overwritten. Mitigation: `install` preserves a `.bak.<timestamp>` copy before the theme apply step. Document clearly in the install command's help text.

docs/superpowers/specs/2026-04-14-release-pipeline-design.md

@@ -0,0 +1,156 @@
+# Release Pipeline Design (Plan 4c)
+
+**Date:** 2026-04-14
+**Scope:** Plan 4c of the Archduino Go rewrite — ship versioned releases and enable one-line install.
+
+## Goal
+
+Let a user install Archduino with a single `curl | bash`, and let the maintainer ship versioned releases with a single `make release`, hosted entirely on the self-hosted Gitea instance at `gitlab.hive-brain.de:2222`.
+
+## Deliverables
+
+1. `bootstrap.sh` — thin curl-piped shim that installs prereqs, downloads the latest release, and execs `archduino install`.
+2. `.goreleaser.yaml` — cross-compile + archive + checksum + changelog + publish to Gitea Releases.
+3. `Makefile` with `release` and `snapshot` targets — driven by `svu` for SemVer bumps.
+4. `.gitea/workflows/release.yml` — tag-triggered workflow that runs goreleaser.
+
+## Components
+
+### 1. `bootstrap.sh` (repo root)
+
+Replaces the legacy `install.sh` (which is Bash-era and will be removed/archived).
+
+Behavior:
+- `set -euo pipefail` throughout.
+- Detect Arch via `/etc/arch-release`; exit 1 with clear message otherwise.
+- `sudo pacman -Sy --needed --noconfirm sudo git curl ca-certificates`.
+- Detect arch: `uname -m` → `x86_64` → `amd64`, `aarch64` → `arm64`. Unknown arch → exit 1.
+- Query Gitea API for latest release:
+  `GET https://gitlab.hive-brain.de/api/v1/repos/MDietermann/Archduino/releases/latest`
+  Extract `tag_name` (e.g. `v0.1.0`) and use it to locate assets.
+- Download `archduino_<version-without-v>_linux_<arch>.tar.gz` and `checksums.txt` into a `mktemp -d`.
+- Verify SHA256 via `sha256sum --check --ignore-missing checksums.txt`; mismatch → exit 1.
+- Extract tarball.
+- Install with sudo:
+  - Binary → `/usr/local/bin/archduino` (0755), overwriting.
+  - `completions/archduino.bash` → `/usr/share/bash-completion/completions/archduino`.
+  - `completions/_archduino` → `/usr/share/zsh/site-functions/_archduino`.
+  - `completions/archduino.fish` → `/usr/share/fish/vendor_completions.d/archduino.fish`.
+- `exec /usr/local/bin/archduino install "$@"` so flags pass through (e.g. `--halt-on-error`).
+
+Usage:
+```
+curl -fsSL https://gitlab.hive-brain.de/MDietermann/Archduino/raw/branch/master/bootstrap.sh | bash
+```
+
+### 2. `.goreleaser.yaml` (repo root)
+
+- `project_name: archduino`
+- `before.hooks:` regenerate shell completions via the cobra `completion` subcommand:
+  - `go run ./cmd/archduino completion bash > completions/archduino.bash`
+  - `go run ./cmd/archduino completion zsh  > completions/_archduino`
+  - `go run ./cmd/archduino completion fish > completions/archduino.fish`
+  - Prerequisite: the `completion` subcommand must be registered on the root cobra command. If not already present, add it as part of the implementation.
+- `builds:`
+  - One entry, `main: ./cmd/archduino`, `binary: archduino`.
+  - `env: [CGO_ENABLED=0]`.
+  - `goos: [linux]`, `goarch: [amd64, arm64]`.
+  - `ldflags: -s -w -X gitlab.hive-brain.de/MDietermann/Archduino/internal/buildinfo.Version={{.Version}} -X ...Commit={{.Commit}} -X ...Date={{.Date}}` (add a small `internal/buildinfo` package to hold these; surface via `archduino version`).
+- `archives:`
+  - Format tar.gz.
+  - Name template `archduino_{{.Version}}_linux_{{.Arch}}`.
+  - Files: binary + `completions/*` + `README.md` + `LICENSE` (add if missing).
+- `checksum: name_template: 'checksums.txt'` (SHA256).
+- `changelog:`
+  - `use: git`
+  - Filters: exclude `^chore:`, `^docs:`, `^test:`, `^ci:`, `^style:`, `Merge pull request`, `Merge branch`.
+  - Groups: `Features` (`^feat`), `Bug fixes` (`^fix|^perf`), `Others` (everything else).
+- `release:`
+  - `gitea_urls.api: https://gitlab.hive-brain.de/api/v1`
+  - `gitea_urls.download: https://gitlab.hive-brain.de`
+
+### 3. `Makefile` (repo root)
+
+Targets:
+- `snapshot` — `goreleaser release --snapshot --clean`. No tagging, no publish. For local build-matrix validation.
+- `release` — SemVer bump flow:
+  1. Assert working tree clean and current branch is `master`; abort otherwise.
+  2. `CURRENT=$$(svu current)` and `NEXT=$$(svu next)`. Display both plus the commit log since `CURRENT`.
+  3. Prompt `Tag $NEXT and push? [y/N]`. Abort on anything but `y`.
+  4. `git tag $$NEXT && git push origin $$NEXT`.
+  The actual release is then produced by CI.
+- `completions` — regenerate completions into `completions/` locally (useful for dev).
+- `build` — local `go build ./cmd/archduino` for quick smoke.
+
+`svu` is a dev dependency; README gains a one-line note: `go install github.com/caarlos0/svu@latest`.
+
+### 4. `.gitea/workflows/release.yml`
+
+- Trigger: `on: push: tags: ['v*']`.
+- `runs-on: ubuntu-latest` (Gitea Actions convention; matches runner labels).
+- Steps:
+  1. `actions/checkout@v4` with `fetch-depth: 0` (goreleaser needs full history for changelog).
+  2. `actions/setup-go@v5` with the Go version pinned in `go.mod`.
+  3. `goreleaser/goreleaser-action@v6` with `args: release --clean`.
+- Env: `GITEA_TOKEN: ${{ secrets.RELEASE_TOKEN }}`. Token is created manually in Gitea UI (repo-scoped, `write:package`/`write:repository` as needed) and stored as a repo secret before first release.
+- Prerequisite (documented, not executed by the plan): a Gitea Actions runner must be registered on the instance. One-time setup outside the scope of this spec.
+
+## Data flow
+
+```
+dev: git commit -m "feat: ..."   (conventional commits)
+dev: make release                → svu computes vX.Y.Z → git tag + push
+Gitea Actions: tag push → goreleaser --clean → Gitea Release published
+                                                 (tarballs + checksums.txt + changelog)
+user: curl … | bash → bootstrap.sh → Gitea API (latest release) → tarball →
+      sha256 verify → /usr/local/bin + completions → exec archduino install
+```
+
+## Versioning
+
+SemVer driven by Conventional Commits via `svu`:
+- `feat:` → minor
+- `fix:` / `perf:` → patch
+- `feat!:` or `BREAKING CHANGE:` footer → major
+- `chore:` / `docs:` / `refactor:` / `test:` / `ci:` / `style:` → no release
+
+First release: `v0.1.0` (seed tag so `svu` has a baseline; manual one-time `git tag v0.1.0`).
+
+## Error handling
+
+- `bootstrap.sh`: checksum mismatch, non-Arch host, arch detection failure, non-200 from API → exit 1 with a specific message; `set -euo pipefail` covers the rest.
+- goreleaser is transactional — the Gitea Release is created after artifacts upload successfully, so a mid-run failure leaves no partial release.
+- `make release` aborts before tagging if the tree is dirty or not on `master`.
+
+## Testing
+
+- `make snapshot` locally verifies the build matrix and archive contents without publishing.
+- `bootstrap.sh` tested against a snapshot tarball in a throwaway Arch container:
+  `docker run --rm -it archlinux bash` → serve the tarball locally → run bootstrap with an overridden base URL (env var hook, e.g. `ARCHDUINO_RELEASE_BASE`) for test runs.
+- No Go test changes; this is all out-of-band release machinery.
+
+## Out of scope (deferred)
+
+- GPG-signed checksums (revisit if/when distribution widens).
+- Debian/Fedora/macOS builds (waiting on multi-distro support elsewhere in the roadmap).
+- Homebrew tap and AUR PKGBUILD (AUR is a natural follow-up but tracked separately).
+- Automated "release PR" bots (release-please / semantic-release) — `svu` + manual `make release` is the chosen trigger.
+
+## File touch list
+
+New:
+- `bootstrap.sh`
+- `.goreleaser.yaml`
+- `Makefile`
+- `.gitea/workflows/release.yml`
+- `internal/buildinfo/buildinfo.go` (tiny — holds `Version`, `Commit`, `Date` vars)
+- `completions/` (gitignored; generated)
+- `LICENSE` (if missing)
+
+Modified:
+- `cmd/archduino/main.go` (register cobra `completion` subcommand if absent; wire a `version` subcommand that prints `buildinfo`).
+- `README.md` (install-via-bootstrap instructions, `svu` note).
+- `.gitignore` (add `dist/`, `completions/`).
+
+Removed/archived:
+- `install.sh` (legacy Bash installer — superseded by `bootstrap.sh` + Go binary).

go.mod

@@ -0,0 +1,42 @@
+module gitlab.hive-brain.de/MDietermann/Archduino
+
+go 1.25.0
+
+require (
+	github.com/charmbracelet/bubbletea v1.3.10
+	github.com/charmbracelet/huh v1.0.0
+	github.com/charmbracelet/lipgloss v1.1.0
+	github.com/charmbracelet/x/exp/teatest v0.0.0-20260413165052-6921c759c913
+	github.com/spf13/cobra v1.10.2
+	gopkg.in/yaml.v3 v3.0.1
+)
+
+require (
+	github.com/atotto/clipboard v0.1.4 // indirect
+	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
+	github.com/aymanbagabas/go-udiff v0.3.1 // indirect
+	github.com/catppuccin/go v0.3.0 // indirect
+	github.com/charmbracelet/bubbles v0.21.1-0.20250623103423-23b8fd6302d7 // indirect
+	github.com/charmbracelet/colorprofile v0.3.2 // indirect
+	github.com/charmbracelet/x/ansi v0.10.1 // indirect
+	github.com/charmbracelet/x/cellbuf v0.0.13 // indirect
+	github.com/charmbracelet/x/exp/golden v0.0.0-20241011142426-46044092ad91 // indirect
+	github.com/charmbracelet/x/exp/strings v0.0.0-20240722160745-212f7b056ed0 // indirect
+	github.com/charmbracelet/x/term v0.2.1 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/mattn/go-localereader v0.0.1 // indirect
+	github.com/mattn/go-runewidth v0.0.16 // indirect
+	github.com/mitchellh/hashstructure/v2 v2.0.2 // indirect
+	github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 // indirect
+	github.com/muesli/cancelreader v0.2.2 // indirect
+	github.com/muesli/termenv v0.16.0 // indirect
+	github.com/rivo/uniseg v0.4.7 // indirect
+	github.com/spf13/pflag v1.0.9 // indirect
+	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
+	golang.org/x/sys v0.36.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+)

go.sum

@@ -0,0 +1,88 @@
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+github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6/go.mod h1:CJlz5H+gyd6CUWT45Oy4q24RdLyn7Md9Vj2/ldJBSIo=
+github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=
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+github.com/muesli/termenv v0.16.0 h1:S5AlUN9dENB57rsbnkPyfdGuWIlkmzJjbFf0Tf5FWUc=
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+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
+github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
+github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
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+github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
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+github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
+go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
+golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
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+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
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+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

install.sh.legacy

@@ -1,4 +1,6 @@
 #!/bin/bash
+# DEPRECATED: This is the legacy Bash installer. The active installer is
+# bootstrap.sh (curl-piped shim) + the archduino Go binary. Kept for reference.
 #
 # Archduino Install — TUI Arduino Development Environment
 # Works on both native Arch Linux and Arch/Ubuntu WSL2
@@ -82,6 +84,7 @@ source "$SCRIPT_DIR/lib/zellij.sh"
 source "$SCRIPT_DIR/lib/neovim.sh"
 source "$SCRIPT_DIR/lib/yazi.sh"
 source "$SCRIPT_DIR/lib/arduino.sh"
+source "$SCRIPT_DIR/lib/renode.sh"
 source "$SCRIPT_DIR/lib/git.sh"
 source "$SCRIPT_DIR/lib/scaffold.sh"
 source "$SCRIPT_DIR/lib/shell-config.sh"
@@ -104,6 +107,9 @@ echo "    arduino-new my-project uno    # scaffold a project"
 echo "    adev                          # launch Arduino workspace"
 echo "    <leader>av                    # compile in Neovim"
 echo "    <leader>au                    # upload in Neovim"
+echo "    wokwi-cli .                   # simulate with Wokwi (visual)"
+echo "    arduino-sim build/fw.elf      # simulate with Renode (GDB)"
+echo "    <leader>ds                    # attach debugger to Renode"
 echo "    theme                         # switch colorscheme"
 echo ""
 warn "A reboot is recommended to apply all changes (shell, groups, PATH)."

internal/config/config.go

@@ -0,0 +1,179 @@
+// Package config loads embedded defaults and optionally merges a user
+// overlay from ~/.config/archduino/overlay.yaml.
+package config
+
+import (
+	_ "embed"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v3"
+)
+
+//go:embed defaults.yaml
+var defaultsYAML []byte
+
+type Packages struct {
+	Base []string `yaml:"base"`
+}
+type ArduinoCLIConfig struct {
+	Version string   `yaml:"version"`
+	URL     string   `yaml:"url"`
+	Cores   []string `yaml:"cores"`
+}
+type ZshPlugin struct {
+	Name string `yaml:"name"`
+	Repo string `yaml:"repo"`
+}
+type ZshConfig struct {
+	OhMyZshRepo string      `yaml:"oh_my_zsh_repo"`
+	Plugins     []ZshPlugin `yaml:"plugins"`
+}
+type ZellijConfig struct {
+	ConfigURL string `yaml:"config_url"`
+}
+type ThemesConfig struct {
+	Source string `yaml:"source"`
+}
+type ShellConfigBlock struct {
+	Name    string `yaml:"name"`
+	File    string `yaml:"file"`
+	Content string `yaml:"content"`
+}
+type ShellConfigSection struct {
+	Blocks []ShellConfigBlock `yaml:"blocks"`
+}
+
+type NeovimConfig struct {
+	NvChadStarterRepo string `yaml:"nvchad_starter_repo"`
+}
+
+type RenodePlatform struct {
+	Name     string `yaml:"name"`
+	ReplPath string `yaml:"repl_path"`
+	Machine  string `yaml:"machine"`
+}
+
+type RenodeConfig struct {
+	WokwiVersion string           `yaml:"wokwi_version"`
+	WokwiURL     string           `yaml:"wokwi_url"`
+	Platforms    []RenodePlatform `yaml:"platforms"`
+}
+
+type Board struct {
+	Name     string `yaml:"name"`
+	FQBN     string `yaml:"fqbn"`
+	Template string `yaml:"template"`
+}
+
+type Scaffolding struct {
+	Boards []Board `yaml:"boards"`
+}
+
+// Config is the fully-resolved runtime configuration.
+type Config struct {
+	Version         int                `yaml:"version"`
+	ExtraPackages   []string           `yaml:"extra_packages"`
+	DisabledModules []string           `yaml:"disabled_modules"`
+	ThemeOverrides  map[string]string  `yaml:"theme_overrides"`
+	Packages        Packages           `yaml:"packages"`
+	Fonts           []string           `yaml:"fonts"`
+	ArduinoCLI      ArduinoCLIConfig   `yaml:"arduino_cli"`
+	Zsh             ZshConfig          `yaml:"zsh"`
+	Zellij          ZellijConfig       `yaml:"zellij"`
+	Themes          ThemesConfig       `yaml:"themes"`
+	ShellConfig     ShellConfigSection `yaml:"shell_config"`
+	Neovim          NeovimConfig       `yaml:"neovim"`
+	Renode          RenodeConfig       `yaml:"renode"`
+	Scaffolding     Scaffolding        `yaml:"scaffolding"`
+}
+
+const currentVersion = 1
+
+// Load returns defaults merged with the overlay at overlayPath (if present).
+// If overlayPath is "", the default location (~/.config/archduino/overlay.yaml)
+// is used. A missing overlay is not an error.
+func Load(overlayPath string) (Config, error) {
+	var cfg Config
+	if err := yaml.Unmarshal(defaultsYAML, &cfg); err != nil {
+		return Config{}, fmt.Errorf("parse embedded defaults: %w", err)
+	}
+
+	if overlayPath == "" {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return cfg, nil
+		}
+		overlayPath = filepath.Join(home, ".config", "archduino", "overlay.yaml")
+	}
+
+	data, err := os.ReadFile(overlayPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return cfg, nil
+		}
+		return Config{}, fmt.Errorf("read overlay %s: %w", overlayPath, err)
+	}
+
+	var overlay Config
+	if err := yaml.Unmarshal(data, &overlay); err != nil {
+		return Config{}, fmt.Errorf("parse overlay %s: %w", overlayPath, err)
+	}
+	if overlay.Version != 0 && overlay.Version != currentVersion {
+		return Config{}, fmt.Errorf("overlay %s: unsupported version %d (want %d)", overlayPath, overlay.Version, currentVersion)
+	}
+
+	return merge(cfg, overlay), nil
+}
+
+func merge(base, over Config) Config {
+	out := base
+	if len(over.ExtraPackages) > 0 {
+		out.ExtraPackages = append(append([]string{}, base.ExtraPackages...), over.ExtraPackages...)
+	}
+	if len(over.DisabledModules) > 0 {
+		out.DisabledModules = append(append([]string{}, base.DisabledModules...), over.DisabledModules...)
+	}
+	if len(over.ThemeOverrides) > 0 {
+		merged := make(map[string]string, len(base.ThemeOverrides)+len(over.ThemeOverrides))
+		for k, v := range base.ThemeOverrides {
+			merged[k] = v
+		}
+		for k, v := range over.ThemeOverrides {
+			merged[k] = v
+		}
+		out.ThemeOverrides = merged
+	}
+	if len(over.Packages.Base) > 0 {
+		out.Packages = over.Packages
+	}
+	if len(over.Fonts) > 0 {
+		out.Fonts = over.Fonts
+	}
+	if over.ArduinoCLI.Version != "" {
+		out.ArduinoCLI = over.ArduinoCLI
+	}
+	if over.Zsh.OhMyZshRepo != "" {
+		out.Zsh = over.Zsh
+	}
+	if over.Zellij.ConfigURL != "" {
+		out.Zellij = over.Zellij
+	}
+	if over.Themes.Source != "" {
+		out.Themes = over.Themes
+	}
+	if len(over.ShellConfig.Blocks) > 0 {
+		out.ShellConfig = over.ShellConfig
+	}
+	if over.Neovim.NvChadStarterRepo != "" {
+		out.Neovim = over.Neovim
+	}
+	if over.Renode.WokwiVersion != "" || len(over.Renode.Platforms) > 0 {
+		out.Renode = over.Renode
+	}
+	if len(over.Scaffolding.Boards) > 0 {
+		out.Scaffolding = over.Scaffolding
+	}
+	return out
+}

internal/config/config_test.go

@@ -0,0 +1,133 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadDefaultsWhenNoOverlay(t *testing.T) {
+	dir := t.TempDir()
+	cfg, err := Load(filepath.Join(dir, "missing.yaml"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Version != 1 {
+		t.Errorf("version = %d", cfg.Version)
+	}
+	if len(cfg.ExtraPackages) != 0 {
+		t.Errorf("extra_packages = %v", cfg.ExtraPackages)
+	}
+}
+
+func TestLoadMergesOverlay(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "overlay.yaml")
+	content := []byte(`
+version: 1
+extra_packages: [htop, ncdu]
+disabled_modules: [renode]
+theme_overrides:
+  starship: /tmp/mine.toml
+`)
+	if err := os.WriteFile(path, content, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := cfg.ExtraPackages; len(got) != 2 || got[0] != "htop" || got[1] != "ncdu" {
+		t.Errorf("extra_packages = %v", got)
+	}
+	if len(cfg.DisabledModules) != 1 || cfg.DisabledModules[0] != "renode" {
+		t.Errorf("disabled_modules = %v", cfg.DisabledModules)
+	}
+	if cfg.ThemeOverrides["starship"] != "/tmp/mine.toml" {
+		t.Errorf("theme_overrides = %v", cfg.ThemeOverrides)
+	}
+}
+
+func TestDefaultsCarryModuleInputs(t *testing.T) {
+	cfg, err := Load("/nonexistent/overlay.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(cfg.Packages.Base) == 0 {
+		t.Error("Packages.Base empty")
+	}
+	if len(cfg.Fonts) == 0 {
+		t.Error("Fonts empty")
+	}
+	if cfg.ArduinoCLI.Version == "" {
+		t.Error("ArduinoCLI.Version empty")
+	}
+	if cfg.ArduinoCLI.URL == "" {
+		t.Error("ArduinoCLI.URL empty")
+	}
+	if cfg.Zsh.OhMyZshRepo == "" {
+		t.Error("Zsh.OhMyZshRepo empty")
+	}
+	if len(cfg.ShellConfig.Blocks) == 0 {
+		t.Error("ShellConfig.Blocks empty")
+	}
+}
+
+func TestDefaultsCarryPlan3bInputs(t *testing.T) {
+	cfg, err := Load("/nonexistent/overlay.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Neovim.NvChadStarterRepo == "" {
+		t.Error("Neovim.NvChadStarterRepo empty")
+	}
+	if cfg.Renode.WokwiVersion == "" {
+		t.Error("Renode.WokwiVersion empty")
+	}
+	if cfg.Renode.WokwiURL == "" {
+		t.Error("Renode.WokwiURL empty")
+	}
+	if len(cfg.Renode.Platforms) == 0 {
+		t.Error("Renode.Platforms empty")
+	}
+	want := map[string]string{"stm32f4": "STM32F4_Discovery", "rp2040": "RP2040", "nrf52840": "nRF52840"}
+	for _, p := range cfg.Renode.Platforms {
+		if want[p.Name] != p.Machine {
+			t.Errorf("platform %q: machine=%q want %q", p.Name, p.Machine, want[p.Name])
+		}
+	}
+}
+
+func TestLoadRejectsUnknownVersion(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "overlay.yaml")
+	if err := os.WriteFile(path, []byte("version: 99\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := Load(path); err == nil {
+		t.Fatal("expected version error")
+	}
+}
+
+func TestDefaultsCarryScaffoldingBoards(t *testing.T) {
+	cfg, err := Load("/nonexistent/overlay.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(cfg.Scaffolding.Boards) < 6 {
+		t.Fatalf("want >= 6 boards, got %d", len(cfg.Scaffolding.Boards))
+	}
+	want := map[string]string{
+		"uno": "arduino:avr:uno", "mega": "arduino:avr:mega", "nano": "arduino:avr:nano",
+		"esp32": "esp32:esp32:esp32", "esp32s3": "esp32:esp32:esp32s3", "esp8266": "esp8266:esp8266:nodemcuv2",
+	}
+	got := map[string]string{}
+	for _, b := range cfg.Scaffolding.Boards {
+		got[b.Name] = b.FQBN
+	}
+	for name, fqbn := range want {
+		if got[name] != fqbn {
+			t.Errorf("board %q: got fqbn %q, want %q", name, got[name], fqbn)
+		}
+	}
+}

internal/config/defaults.yaml

@@ -0,0 +1,108 @@
+version: 1
+extra_packages: []
+disabled_modules: []
+theme_overrides: {}
+
+packages:
+  base:
+    - base-devel
+    - git
+    - curl
+    - wget
+    - unzip
+    - zip
+    - tree
+    - htop
+    - fastfetch
+    - ripgrep
+    - fd
+    - bat
+    - eza
+    - jq
+    - zsh
+    - clang
+    - ca-certificates
+
+fonts:
+  - ttf-jetbrains-mono-nerd
+
+arduino_cli:
+  version: "0.35.3"
+  url: "https://github.com/arduino/arduino-cli/releases/download/v0.35.3/arduino-cli_0.35.3_Linux_64bit.tar.gz"
+  cores:
+    - arduino:avr
+
+zsh:
+  oh_my_zsh_repo: "https://github.com/ohmyzsh/ohmyzsh.git"
+  plugins:
+    - name: zsh-autosuggestions
+      repo: https://github.com/zsh-users/zsh-autosuggestions
+    - name: zsh-syntax-highlighting
+      repo: https://github.com/zsh-users/zsh-syntax-highlighting.git
+
+zellij:
+  config_url: ""
+
+themes:
+  source: "lib/themes"
+
+shell_config:
+  blocks:
+    - name: archduino-path
+      file: ".zshrc"
+      content: |
+        export PATH="$HOME/.local/bin:$PATH"
+    - name: archduino-editor
+      file: ".zshrc"
+      content: |
+        export EDITOR="nvim"
+        export VISUAL="nvim"
+    - name: archduino-starship
+      file: ".zshrc"
+      content: |
+        eval "$(starship init zsh)"
+    - name: archduino-zellij
+      file: ".zshrc"
+      content: |
+        if [[ -z "$ZELLIJ" ]]; then
+          zellij attach --create archduino
+        fi
+    - name: archduino-aliases
+      file: ".zshrc"
+      content: |
+        alias adev="zellij --layout arduino"
+        alias ac="arduino-cli"
+        alias acc="arduino-cli compile"
+        alias acu="arduino-cli upload"
+        alias acm="arduino-cli monitor"
+        alias acb="arduino-cli board list"
+        alias lg="lazygit"
+        alias v="nvim"
+        alias y="yazi"
+        alias theme="archduino-theme"
+
+neovim:
+  nvchad_starter_repo: "https://github.com/NvChad/starter"
+
+renode:
+  wokwi_version: "0.26.1"
+  wokwi_url: "https://github.com/wokwi/wokwi-cli/releases/download/v0.26.1/wokwi-cli-linuxstatic-x64"
+  platforms:
+    - name: stm32f4
+      repl_path: "platforms/boards/stm32f4_discovery.repl"
+      machine: "STM32F4_Discovery"
+    - name: rp2040
+      repl_path: "platforms/cpus/rp2040.repl"
+      machine: "RP2040"
+    - name: nrf52840
+      repl_path: "platforms/cpus/nrf52840.repl"
+      machine: "nRF52840"
+
+scaffolding:
+  boards:
+    - {name: uno, fqbn: "arduino:avr:uno", template: uno}
+    - {name: mega, fqbn: "arduino:avr:mega", template: mega}
+    - {name: nano, fqbn: "arduino:avr:nano", template: nano}
+    - {name: esp32, fqbn: "esp32:esp32:esp32", template: esp32}
+    - {name: esp32s3, fqbn: "esp32:esp32:esp32s3", template: esp32s3}
+    - {name: esp8266, fqbn: "esp8266:esp8266:nodemcuv2", template: esp8266}

internal/engine/dag.go

@@ -0,0 +1,91 @@
+package engine
+
+import (
+	"fmt"
+	"sort"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+// TopoSort returns module IDs in a valid dependency order.
+// Ties are broken alphabetically for deterministic output.
+// Returns an error on unknown deps or cycles.
+func TopoSort(metas []module.Meta) ([]string, error) {
+	known := make(map[string]bool, len(metas))
+	for _, m := range metas {
+		known[m.ID] = true
+	}
+	for _, m := range metas {
+		for _, d := range m.Deps {
+			if !known[d] {
+				return nil, fmt.Errorf("module %q depends on unknown %q", m.ID, d)
+			}
+		}
+	}
+
+	// Kahn's algorithm with alphabetical tie-breaking.
+	indeg := make(map[string]int, len(metas))
+	children := make(map[string][]string, len(metas))
+	for _, m := range metas {
+		if _, ok := indeg[m.ID]; !ok {
+			indeg[m.ID] = 0
+		}
+		for _, d := range m.Deps {
+			indeg[m.ID]++
+			children[d] = append(children[d], m.ID)
+		}
+	}
+
+	var ready []string
+	for id, d := range indeg {
+		if d == 0 {
+			ready = append(ready, id)
+		}
+	}
+	sort.Strings(ready)
+
+	var order []string
+	for len(ready) > 0 {
+		next := ready[0]
+		ready = ready[1:]
+		order = append(order, next)
+		kids := append([]string(nil), children[next]...)
+		sort.Strings(kids)
+		for _, c := range kids {
+			indeg[c]--
+			if indeg[c] == 0 {
+				ready = append(ready, c)
+				sort.Strings(ready)
+			}
+		}
+	}
+
+	if len(order) != len(metas) {
+		return nil, fmt.Errorf("dependency cycle detected among modules")
+	}
+	return order, nil
+}
+
+// Descendants returns the set of module IDs transitively downstream of root.
+// Root itself is NOT included.
+func Descendants(metas []module.Meta, root string) map[string]bool {
+	children := make(map[string][]string)
+	for _, m := range metas {
+		for _, d := range m.Deps {
+			children[d] = append(children[d], m.ID)
+		}
+	}
+	out := make(map[string]bool)
+	var walk func(string)
+	walk = func(id string) {
+		for _, c := range children[id] {
+			if out[c] {
+				continue
+			}
+			out[c] = true
+			walk(c)
+		}
+	}
+	walk(root)
+	return out
+}

internal/engine/dag_test.go

@@ -0,0 +1,79 @@
+package engine
+
+import (
+	"reflect"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+func TestTopoSort(t *testing.T) {
+	cases := []struct {
+		name  string
+		metas []module.Meta
+		want  []string
+		err   bool
+	}{
+		{
+			name:  "linear chain",
+			metas: []module.Meta{{ID: "a"}, {ID: "b", Deps: []string{"a"}}, {ID: "c", Deps: []string{"b"}}},
+			want:  []string{"a", "b", "c"},
+		},
+		{
+			name:  "independent modules sorted alphabetically",
+			metas: []module.Meta{{ID: "c"}, {ID: "a"}, {ID: "b"}},
+			want:  []string{"a", "b", "c"},
+		},
+		{
+			name:  "diamond",
+			metas: []module.Meta{{ID: "a"}, {ID: "b", Deps: []string{"a"}}, {ID: "c", Deps: []string{"a"}}, {ID: "d", Deps: []string{"b", "c"}}},
+			want:  []string{"a", "b", "c", "d"},
+		},
+		{
+			name:  "unknown dep",
+			metas: []module.Meta{{ID: "a", Deps: []string{"missing"}}},
+			err:   true,
+		},
+		{
+			name:  "cycle",
+			metas: []module.Meta{{ID: "a", Deps: []string{"b"}}, {ID: "b", Deps: []string{"a"}}},
+			err:   true,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := TopoSort(tc.metas)
+			if tc.err {
+				if err == nil {
+					t.Fatalf("want error, got nil (order=%v)", got)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Fatalf("order = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestDescendants(t *testing.T) {
+	metas := []module.Meta{
+		{ID: "a"},
+		{ID: "b", Deps: []string{"a"}},
+		{ID: "c", Deps: []string{"a"}},
+		{ID: "d", Deps: []string{"b"}},
+		{ID: "e"}, // independent
+	}
+	got := Descendants(metas, "a")
+	want := map[string]bool{"b": true, "c": true, "d": true}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("descendants(a) = %v, want %v", got, want)
+	}
+
+	if len(Descendants(metas, "e")) != 0 {
+		t.Fatalf("descendants(e) should be empty")
+	}
+}

internal/engine/engine.go

@@ -0,0 +1,207 @@
+package engine
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+// RunOptions controls a single engine run.
+type RunOptions struct {
+	Selected    []string // module IDs to run; empty = all
+	DryRun      bool     // Detect + Plan only, no Apply/Verify
+	HaltOnError bool     // stop at first failure instead of continuing siblings
+	// Force, when true, skips Detect and calls PlanForce on every module
+	// so each one produces a from-scratch plan regardless of current state.
+	Force    bool
+	Reporter module.Reporter
+}
+
+// ModuleStatus is the terminal state of a module within a run.
+type ModuleStatus string
+
+const (
+	StatusSucceeded ModuleStatus = "succeeded"
+	StatusFailed    ModuleStatus = "failed"
+	StatusSkipped   ModuleStatus = "skipped"
+	StatusPlanned   ModuleStatus = "planned" // dry-run only
+)
+
+// ModuleResult captures what happened for one module.
+type ModuleResult struct {
+	ID     string
+	Status ModuleStatus
+	Plan   module.Plan
+	Err    error
+}
+
+// Summary aggregates results.
+type Summary struct {
+	Results []ModuleResult
+}
+
+// Counts returns (succeeded, failed, skipped).
+func (s Summary) Counts() (int, int, int) {
+	var ok, fail, skip int
+	for _, r := range s.Results {
+		switch r.Status {
+		case StatusSucceeded, StatusPlanned:
+			ok++
+		case StatusFailed:
+			fail++
+		case StatusSkipped:
+			skip++
+		}
+	}
+	return ok, fail, skip
+}
+
+// Run drives the selected modules through the four phases in DAG order.
+// Parallelism is intentionally omitted in this foundation; a later plan
+// will introduce it. Sequential execution is a correct baseline.
+func Run(ctx context.Context, reg *module.Registry, opts RunOptions) (Summary, error) {
+	mods, err := resolveSelection(reg, opts.Selected)
+	if err != nil {
+		return Summary{}, err
+	}
+
+	metas := make([]module.Meta, 0, len(mods))
+	for _, m := range mods {
+		metas = append(metas, m.Meta())
+	}
+	order, err := TopoSort(metas)
+	if err != nil {
+		return Summary{}, fmt.Errorf("module graph: %w", err)
+	}
+
+	byID := make(map[string]module.Module, len(mods))
+	for _, m := range mods {
+		byID[m.Meta().ID] = m
+	}
+
+	results := make(map[string]*ModuleResult, len(mods))
+	skipped := make(map[string]bool)
+
+	for _, id := range order {
+		if skipped[id] {
+			results[id] = &ModuleResult{ID: id, Status: StatusSkipped, Err: errors.New("skipped: upstream failed")}
+			continue
+		}
+		m := byID[id]
+		res := &ModuleResult{ID: id}
+		results[id] = res
+
+		var (
+			plan module.Plan
+			err  error
+		)
+		if opts.Force {
+			plan, err = m.PlanForce(ctx)
+			if err != nil {
+				res.Status = StatusFailed
+				res.Err = fmt.Errorf("plan-force: %w", err)
+				markFailed(metas, id, skipped)
+				if opts.HaltOnError {
+					break
+				}
+				continue
+			}
+		} else {
+			state, derr := m.Detect(ctx)
+			if derr != nil {
+				res.Status = StatusFailed
+				res.Err = fmt.Errorf("detect: %w", derr)
+				markFailed(metas, id, skipped)
+				if opts.HaltOnError {
+					break
+				}
+				continue
+			}
+
+			plan, err = m.Plan(ctx, state)
+			if err != nil {
+				res.Status = StatusFailed
+				res.Err = fmt.Errorf("plan: %w", err)
+				markFailed(metas, id, skipped)
+				if opts.HaltOnError {
+					break
+				}
+				continue
+			}
+		}
+		res.Plan = plan
+
+		if opts.DryRun {
+			res.Status = StatusPlanned
+			continue
+		}
+
+		if err := m.Apply(ctx, plan, opts.Reporter); err != nil {
+			res.Status = StatusFailed
+			res.Err = fmt.Errorf("apply: %w", err)
+			markFailed(metas, id, skipped)
+			if opts.HaltOnError {
+				break
+			}
+			continue
+		}
+		if err := m.Verify(ctx); err != nil {
+			res.Status = StatusFailed
+			res.Err = fmt.Errorf("verify: %w", err)
+			markFailed(metas, id, skipped)
+			if opts.HaltOnError {
+				break
+			}
+			continue
+		}
+		res.Status = StatusSucceeded
+	}
+
+	summary := Summary{}
+	// Emit results in topo order for stable output.
+	ids := make([]string, 0, len(results))
+	for id := range results {
+		ids = append(ids, id)
+	}
+	sort.SliceStable(ids, func(i, j int) bool {
+		return indexOf(order, ids[i]) < indexOf(order, ids[j])
+	})
+	for _, id := range ids {
+		summary.Results = append(summary.Results, *results[id])
+	}
+	return summary, nil
+}
+
+func resolveSelection(reg *module.Registry, selected []string) ([]module.Module, error) {
+	all := reg.All()
+	if len(selected) == 0 {
+		return all, nil
+	}
+	out := make([]module.Module, 0, len(selected))
+	for _, id := range selected {
+		m, ok := reg.Get(id)
+		if !ok {
+			return nil, fmt.Errorf("unknown module %q", id)
+		}
+		out = append(out, m)
+	}
+	return out, nil
+}
+
+func markFailed(metas []module.Meta, id string, skipped map[string]bool) {
+	for d := range Descendants(metas, id) {
+		skipped[d] = true
+	}
+}
+
+func indexOf(s []string, v string) int {
+	for i, x := range s {
+		if x == v {
+			return i
+		}
+	}
+	return -1
+}

internal/engine/engine_test.go

@@ -0,0 +1,196 @@
+package engine
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+// scriptedModule lets tests control what each phase returns.
+type scriptedModule struct {
+	id        string
+	deps      []string
+	detect    func() (module.State, error)
+	plan      func() (module.Plan, error)
+	planForce func() (module.Plan, error)
+	apply     func() error
+	verify    func() error
+
+	detectCalls    int
+	planCalls      int
+	planForceCalls int
+}
+
+func (s *scriptedModule) Meta() module.Meta { return module.Meta{ID: s.id, Name: s.id, Deps: s.deps} }
+func (s *scriptedModule) Detect(ctx context.Context) (module.State, error) {
+	s.detectCalls++
+	if s.detect != nil {
+		return s.detect()
+	}
+	return nil, nil
+}
+func (s *scriptedModule) Plan(ctx context.Context, _ module.State) (module.Plan, error) {
+	s.planCalls++
+	if s.plan != nil {
+		return s.plan()
+	}
+	return module.Plan{}, nil
+}
+func (s *scriptedModule) PlanForce(ctx context.Context) (module.Plan, error) {
+	s.planForceCalls++
+	if s.planForce != nil {
+		return s.planForce()
+	}
+	if s.plan != nil {
+		return s.plan()
+	}
+	return module.Plan{}, nil
+}
+func (s *scriptedModule) Apply(ctx context.Context, _ module.Plan, _ module.Reporter) error {
+	if s.apply != nil {
+		return s.apply()
+	}
+	return nil
+}
+func (s *scriptedModule) Verify(ctx context.Context) error {
+	if s.verify != nil {
+		return s.verify()
+	}
+	return nil
+}
+
+func newReg(t *testing.T, mods ...module.Module) *module.Registry {
+	t.Helper()
+	r := module.NewRegistry()
+	for _, m := range mods {
+		if err := r.Register(m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return r
+}
+
+func TestRunAllSucceed(t *testing.T) {
+	reg := newReg(t,
+		&scriptedModule{id: "a"},
+		&scriptedModule{id: "b", deps: []string{"a"}},
+	)
+	sum, err := Run(context.Background(), reg, RunOptions{Reporter: NewBufferedReporter()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	ok, fail, skip := sum.Counts()
+	if ok != 2 || fail != 0 || skip != 0 {
+		t.Fatalf("counts = (%d,%d,%d)", ok, fail, skip)
+	}
+	if sum.Results[0].ID != "a" || sum.Results[1].ID != "b" {
+		t.Fatalf("order = %v", sum.Results)
+	}
+}
+
+func TestRunDryRunDoesNotApply(t *testing.T) {
+	applied := false
+	reg := newReg(t, &scriptedModule{
+		id:    "a",
+		apply: func() error { applied = true; return nil },
+	})
+	sum, err := Run(context.Background(), reg, RunOptions{DryRun: true, Reporter: NewBufferedReporter()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if applied {
+		t.Fatal("Apply was called during dry-run")
+	}
+	if sum.Results[0].Status != StatusPlanned {
+		t.Fatalf("status = %v", sum.Results[0].Status)
+	}
+}
+
+func TestRunFailureSkipsDescendantsContinuesSiblings(t *testing.T) {
+	reg := newReg(t,
+		&scriptedModule{id: "root"},
+		&scriptedModule{id: "fails", deps: []string{"root"}, apply: func() error { return errors.New("boom") }},
+		&scriptedModule{id: "child", deps: []string{"fails"}},
+		&scriptedModule{id: "sibling", deps: []string{"root"}},
+	)
+	sum, err := Run(context.Background(), reg, RunOptions{Reporter: NewBufferedReporter()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	status := map[string]ModuleStatus{}
+	for _, r := range sum.Results {
+		status[r.ID] = r.Status
+	}
+	if status["root"] != StatusSucceeded {
+		t.Errorf("root = %v", status["root"])
+	}
+	if status["fails"] != StatusFailed {
+		t.Errorf("fails = %v", status["fails"])
+	}
+	if status["child"] != StatusSkipped {
+		t.Errorf("child = %v", status["child"])
+	}
+	if status["sibling"] != StatusSucceeded {
+		t.Errorf("sibling = %v (should have run)", status["sibling"])
+	}
+}
+
+func TestRunHaltOnError(t *testing.T) {
+	reg := newReg(t,
+		&scriptedModule{id: "a", apply: func() error { return errors.New("nope") }},
+		&scriptedModule{id: "b"}, // independent
+	)
+	sum, err := Run(context.Background(), reg, RunOptions{HaltOnError: true, Reporter: NewBufferedReporter()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// "b" should not appear in results because we halted before reaching it.
+	for _, r := range sum.Results {
+		if r.ID == "b" {
+			t.Fatalf("b was run despite HaltOnError")
+		}
+	}
+}
+
+func TestRunUnknownModule(t *testing.T) {
+	reg := module.NewRegistry()
+	_, err := Run(context.Background(), reg, RunOptions{Selected: []string{"ghost"}})
+	if err == nil {
+		t.Fatal("expected error for unknown module")
+	}
+}
+
+func TestRunForceSkipsDetectAndCallsPlanForce(t *testing.T) {
+	mod := &scriptedModule{
+		id: "a",
+		detect: func() (module.State, error) {
+			panic("Detect must not be called when Force=true")
+		},
+		planForce: func() (module.Plan, error) {
+			return module.Plan{Actions: []module.Action{{Description: "forced"}}}, nil
+		},
+	}
+	reg := newReg(t, mod)
+	sum, err := Run(context.Background(), reg, RunOptions{Force: true, Reporter: NewBufferedReporter()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if mod.planForceCalls != 1 {
+		t.Errorf("planForceCalls = %d, want 1", mod.planForceCalls)
+	}
+	if mod.detectCalls != 0 {
+		t.Errorf("detectCalls = %d, want 0", mod.detectCalls)
+	}
+	if mod.planCalls != 0 {
+		t.Errorf("planCalls = %d, want 0", mod.planCalls)
+	}
+	ok, fail, skip := sum.Counts()
+	if ok != 1 || fail != 0 || skip != 0 {
+		t.Fatalf("counts = (%d,%d,%d)", ok, fail, skip)
+	}
+	if len(sum.Results[0].Plan.Actions) != 1 {
+		t.Fatalf("expected 1 action in plan, got %d", len(sum.Results[0].Plan.Actions))
+	}
+}

internal/engine/reporter.go

@@ -0,0 +1,80 @@
+// Package engine runs modules through the Detect/Plan/Apply/Verify phases.
+package engine
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+// Event is a single item streamed from a module during Apply.
+type Event struct {
+	ModuleID string
+	Kind     EventKind
+	Current  int
+	Total    int
+	Message  string
+}
+
+type EventKind int
+
+const (
+	EventProgress EventKind = iota
+	EventLog
+)
+
+// BufferedReporter stores every event in memory. Used in tests.
+type BufferedReporter struct {
+	mu     sync.Mutex
+	events []Event
+}
+
+func NewBufferedReporter() *BufferedReporter { return &BufferedReporter{} }
+
+func (b *BufferedReporter) Progress(id string, current, total int, msg string) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.events = append(b.events, Event{ModuleID: id, Kind: EventProgress, Current: current, Total: total, Message: msg})
+}
+
+func (b *BufferedReporter) Log(id, line string) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.events = append(b.events, Event{ModuleID: id, Kind: EventLog, Message: line})
+}
+
+func (b *BufferedReporter) Events() []Event {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	out := make([]Event, len(b.events))
+	copy(out, b.events)
+	return out
+}
+
+// PlainReporter writes human-readable lines to w. Concurrency-safe.
+type PlainReporter struct {
+	mu sync.Mutex
+	w  io.Writer
+}
+
+func NewPlainReporter(w io.Writer) *PlainReporter { return &PlainReporter{w: w} }
+
+func (p *PlainReporter) Progress(id string, current, total int, msg string) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	fmt.Fprintf(p.w, "[%s] (%d/%d) %s\n", id, current, total, msg)
+}
+
+func (p *PlainReporter) Log(id, line string) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	fmt.Fprintf(p.w, "[%s] %s\n", id, line)
+}
+
+// Compile-time guarantee both types satisfy module.Reporter.
+var (
+	_ module.Reporter = (*BufferedReporter)(nil)
+	_ module.Reporter = (*PlainReporter)(nil)
+)

internal/engine/reporter_test.go

@@ -0,0 +1,56 @@
+package engine
+
+import (
+	"bytes"
+	"strings"
+	"sync"
+	"testing"
+)
+
+func TestBufferedReporterRecordsEventsInOrder(t *testing.T) {
+	r := NewBufferedReporter()
+	r.Progress("m", 1, 3, "step 1")
+	r.Log("m", "hello")
+	r.Progress("m", 2, 3, "step 2")
+
+	ev := r.Events()
+	if len(ev) != 3 {
+		t.Fatalf("want 3 events, got %d", len(ev))
+	}
+	if ev[0].Kind != EventProgress || ev[0].Current != 1 {
+		t.Errorf("event[0] = %+v", ev[0])
+	}
+	if ev[1].Kind != EventLog || ev[1].Message != "hello" {
+		t.Errorf("event[1] = %+v", ev[1])
+	}
+}
+
+func TestBufferedReporterIsConcurrencySafe(t *testing.T) {
+	r := NewBufferedReporter()
+	var wg sync.WaitGroup
+	for i := 0; i < 50; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			r.Progress("m", i, 50, "x")
+		}(i)
+	}
+	wg.Wait()
+	if got := len(r.Events()); got != 50 {
+		t.Fatalf("want 50 events, got %d", got)
+	}
+}
+
+func TestPlainReporterFormat(t *testing.T) {
+	var buf bytes.Buffer
+	r := NewPlainReporter(&buf)
+	r.Progress("packages", 2, 10, "installing tio")
+	r.Log("packages", "pacman: done")
+
+	out := buf.String()
+	for _, want := range []string{"[packages] (2/10) installing tio", "[packages] pacman: done"} {
+		if !strings.Contains(out, want) {
+			t.Errorf("output missing %q; got:\n%s", want, out)
+		}
+	}
+}

internal/module/module.go

@@ -0,0 +1,67 @@
+// Package module defines the four-phase contract every installable unit
+// implements, along with the value types exchanged with the engine.
+package module
+
+import "context"
+
+// Meta is static, declarative information about a module.
+type Meta struct {
+	ID          string   // stable machine identifier, e.g. "packages"
+	Name        string   // human label, e.g. "Base packages"
+	Description string   // one-line summary for TUI
+	Deps        []string // IDs of modules that must complete before this one
+}
+
+// State is an opaque, module-defined snapshot of current system state.
+// The engine never inspects it; it is threaded from Detect → Plan.
+type State any
+
+// ActionKind categorizes what an Action does, for UI grouping only.
+type ActionKind int
+
+const (
+	ActionUnknown ActionKind = iota
+	ActionPackageInstall
+	ActionFileWrite
+	ActionSymlink
+	ActionCommand
+	ActionGitClone
+	ActionGroupAdd
+)
+
+// Action is a single planned change with a human-readable description.
+type Action struct {
+	Description string
+	Kind        ActionKind
+	Exec        func(ctx context.Context) error
+}
+
+// Plan is an ordered list of actions returned by Module.Plan.
+type Plan struct {
+	Actions []Action
+}
+
+// IsEmpty reports whether the plan would make no changes.
+func (p Plan) IsEmpty() bool { return len(p.Actions) == 0 }
+
+// Module is the four-phase contract.
+type Module interface {
+	Meta() Meta
+	Detect(ctx context.Context) (State, error)
+	Plan(ctx context.Context, current State) (Plan, error)
+	// PlanForce returns a plan that reapplies the module unconditionally,
+	// ignoring current detected state. Used by `archduino install --force`.
+	// Implementations should produce a plan equivalent to a from-scratch
+	// install — reinstall packages without pacman's --needed guard and
+	// rewrite managed config files.
+	PlanForce(ctx context.Context) (Plan, error)
+	Apply(ctx context.Context, plan Plan, r Reporter) error
+	Verify(ctx context.Context) error
+}
+
+// Reporter is how modules stream progress events. Defined here as an
+// interface to avoid an import cycle with the engine package.
+type Reporter interface {
+	Progress(moduleID string, current, total int, message string)
+	Log(moduleID, line string)
+}

internal/module/registry.go

@@ -0,0 +1,56 @@
+package module
+
+import (
+	"fmt"
+	"sort"
+	"sync"
+)
+
+// Registry holds all known modules keyed by Meta.ID.
+type Registry struct {
+	mu      sync.RWMutex
+	modules map[string]Module
+}
+
+// NewRegistry returns an empty registry.
+func NewRegistry() *Registry {
+	return &Registry{modules: make(map[string]Module)}
+}
+
+// Register adds a module. Returns an error if the ID is already present
+// or empty. Safe for concurrent use.
+func (r *Registry) Register(m Module) error {
+	id := m.Meta().ID
+	if id == "" {
+		return fmt.Errorf("module has empty ID")
+	}
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if _, dup := r.modules[id]; dup {
+		return fmt.Errorf("module %q already registered", id)
+	}
+	r.modules[id] = m
+	return nil
+}
+
+// Get returns the module with the given ID, or (nil, false) if absent.
+func (r *Registry) Get(id string) (Module, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	m, ok := r.modules[id]
+	return m, ok
+}
+
+// All returns all registered modules sorted by ID for determinism.
+func (r *Registry) All() []Module {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	out := make([]Module, 0, len(r.modules))
+	for _, m := range r.modules {
+		out = append(out, m)
+	}
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].Meta().ID < out[j].Meta().ID
+	})
+	return out
+}

internal/module/registry_test.go

@@ -0,0 +1,61 @@
+package module
+
+import (
+	"context"
+	"testing"
+)
+
+type fakeModule struct {
+	id   string
+	deps []string
+}
+
+func (f fakeModule) Meta() Meta                                  { return Meta{ID: f.id, Name: f.id, Deps: f.deps} }
+func (f fakeModule) Detect(context.Context) (State, error)       { return nil, nil }
+func (f fakeModule) Plan(context.Context, State) (Plan, error)   { return Plan{}, nil }
+func (f fakeModule) PlanForce(context.Context) (Plan, error)     { return Plan{}, nil }
+func (f fakeModule) Apply(context.Context, Plan, Reporter) error { return nil }
+func (f fakeModule) Verify(context.Context) error                { return nil }
+
+func TestRegistry(t *testing.T) {
+	t.Run("register then get", func(t *testing.T) {
+		r := NewRegistry()
+		if err := r.Register(fakeModule{id: "a"}); err != nil {
+			t.Fatal(err)
+		}
+		m, ok := r.Get("a")
+		if !ok || m.Meta().ID != "a" {
+			t.Fatalf("want module a, got %v ok=%v", m, ok)
+		}
+	})
+
+	t.Run("duplicate register errors", func(t *testing.T) {
+		r := NewRegistry()
+		_ = r.Register(fakeModule{id: "a"})
+		if err := r.Register(fakeModule{id: "a"}); err == nil {
+			t.Fatal("expected duplicate error")
+		}
+	})
+
+	t.Run("empty id errors", func(t *testing.T) {
+		r := NewRegistry()
+		if err := r.Register(fakeModule{id: ""}); err == nil {
+			t.Fatal("expected empty-id error")
+		}
+	})
+
+	t.Run("all is sorted by id", func(t *testing.T) {
+		r := NewRegistry()
+		_ = r.Register(fakeModule{id: "b"})
+		_ = r.Register(fakeModule{id: "a"})
+		_ = r.Register(fakeModule{id: "c"})
+		all := r.All()
+		got := []string{all[0].Meta().ID, all[1].Meta().ID, all[2].Meta().ID}
+		want := []string{"a", "b", "c"}
+		for i := range got {
+			if got[i] != want[i] {
+				t.Fatalf("All() = %v, want %v", got, want)
+			}
+		}
+	})
+}

internal/modules/arduinocli/arduinocli.go

@@ -0,0 +1,172 @@
+// Package arduinocli installs arduino-cli and its configured cores.
+package arduinocli
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	cfg    config.ArduinoCLIConfig
+	runner platform.Runner
+}
+
+func New(cfg config.ArduinoCLIConfig, r platform.Runner) Module {
+	return Module{cfg: cfg, runner: r}
+}
+
+type state struct {
+	BinaryPath      string
+	BinaryInstalled bool
+	MissingCores    []string
+}
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "arduinocli", Name: "arduino-cli", Description: "Install arduino-cli and cores."}
+}
+
+func binaryPath() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".local", "bin", "arduino-cli"), nil
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	bp, err := binaryPath()
+	if err != nil {
+		return nil, err
+	}
+	s := state{BinaryPath: bp}
+	if _, err := os.Stat(bp); err == nil {
+		s.BinaryInstalled = true
+		out, _ := m.runner.Output(ctx, bp, "core", "list")
+		for _, core := range m.cfg.Cores {
+			if !bytes.Contains(out, []byte(core)) {
+				s.MissingCores = append(s.MissingCores, core)
+			}
+		}
+	} else {
+		s.MissingCores = append([]string{}, m.cfg.Cores...)
+	}
+	return s, nil
+}
+
+// downloadBinary fetches, extracts, and installs arduino-cli to bp.
+func (m Module) downloadBinary(ctx context.Context, bp string) error {
+	tmpDir, err := os.MkdirTemp("", "arduinocli-")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmpDir)
+	archive := filepath.Join(tmpDir, "arduino-cli.tar.gz")
+	if err := platform.Download(ctx, m.cfg.URL, archive, 0o644); err != nil {
+		return err
+	}
+	if err := platform.ExtractTarGz(ctx, archive, tmpDir); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(bp), 0o755); err != nil {
+		return err
+	}
+	data, err := os.ReadFile(filepath.Join(tmpDir, "arduino-cli"))
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(bp, data, 0o755)
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	var actions []module.Action
+	if !s.BinaryInstalled {
+		bp := s.BinaryPath
+		actions = append(actions, module.Action{
+			Description: "download + install arduino-cli " + m.cfg.Version,
+			Kind:        module.ActionFileWrite,
+			Exec:        func(ctx context.Context) error { return m.downloadBinary(ctx, bp) },
+		})
+	}
+	for _, core := range s.MissingCores {
+		core := core
+		actions = append(actions, module.Action{
+			Description: "arduino-cli core update-index (for " + core + ")",
+			Kind:        module.ActionCommand,
+			Exec: func(ctx context.Context) error {
+				return m.runner.Run(ctx, s.BinaryPath, "core", "update-index")
+			},
+		})
+		actions = append(actions, module.Action{
+			Description: "arduino-cli core install " + core,
+			Kind:        module.ActionCommand,
+			Exec: func(ctx context.Context) error {
+				return m.runner.Run(ctx, s.BinaryPath, "core", "install", core)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	s := st.(state)
+	if !s.BinaryInstalled {
+		return fmt.Errorf("arduino-cli binary missing")
+	}
+	if len(s.MissingCores) > 0 {
+		return fmt.Errorf("cores missing: %v", s.MissingCores)
+	}
+	return nil
+}
+
+// PlanForce redownloads the arduino-cli binary, refreshes the core index,
+// and reinstalls every configured core unconditionally. arduino-cli's
+// `core install` is idempotent, so reissuing it is safe.
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	bp, err := binaryPath()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	actions := []module.Action{
+		{
+			Description: "redownload + reinstall arduino-cli " + m.cfg.Version + " (force)",
+			Kind:        module.ActionFileWrite,
+			Exec:        func(ctx context.Context) error { return m.downloadBinary(ctx, bp) },
+		},
+		{
+			Description: "arduino-cli core update-index (force)",
+			Kind:        module.ActionCommand,
+			Exec:        func(ctx context.Context) error { return m.runner.Run(ctx, bp, "core", "update-index") },
+		},
+	}
+	for _, core := range m.cfg.Cores {
+		core := core
+		actions = append(actions, module.Action{
+			Description: "arduino-cli core install " + core + " (force)",
+			Kind:        module.ActionCommand,
+			Exec:        func(ctx context.Context) error { return m.runner.Run(ctx, bp, "core", "install", core) },
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/arduinocli/arduinocli_test.go

@@ -0,0 +1,154 @@
+package arduinocli
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+type fakeRunner struct {
+	runCalls    [][]string
+	outCalls    [][]string
+	coreListOut []byte
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if filepath.Base(name) == "arduino-cli" && len(args) >= 2 && args[0] == "core" && args[1] == "list" {
+		return f.coreListOut, nil
+	}
+	return nil, nil
+}
+
+type nop struct{}
+
+func (nop) Progress(string, int, int, string) {}
+func (nop) Log(string, string)                {}
+
+func makeTarGz(t *testing.T, entries map[string][]byte) string {
+	t.Helper()
+	p := filepath.Join(t.TempDir(), "a.tgz")
+	f, _ := os.Create(p)
+	gz := gzip.NewWriter(f)
+	tw := tar.NewWriter(gz)
+	for name, data := range entries {
+		_ = tw.WriteHeader(&tar.Header{Name: name, Mode: 0o755, Size: int64(len(data))})
+		_, _ = tw.Write(data)
+	}
+	tw.Close()
+	gz.Close()
+	f.Close()
+	return p
+}
+
+func TestArduinoCLIDownloadsAndInstallsCore(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	archive := makeTarGz(t, map[string][]byte{"arduino-cli": []byte("#!/bin/sh\n")})
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		data, _ := os.ReadFile(archive)
+		w.Write(data)
+	}))
+	defer srv.Close()
+
+	r := &fakeRunner{coreListOut: []byte("ID  Installed\n")}
+	m := New(config.ArduinoCLIConfig{
+		Version: "1.0.0",
+		URL:     srv.URL + "/arduino-cli.tgz",
+		Cores:   []string{"arduino:avr"},
+	}, r)
+
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := os.Stat(filepath.Join(home, ".local", "bin", "arduino-cli")); err != nil {
+		t.Fatalf("binary not installed: %v", err)
+	}
+	sawCore := false
+	for _, c := range r.runCalls {
+		if filepath.Base(c[0]) == "arduino-cli" && len(c) >= 4 && c[1] == "core" && c[2] == "install" && c[3] == "arduino:avr" {
+			sawCore = true
+		}
+	}
+	if !sawCore {
+		t.Fatalf("core install not run; calls=%v", r.runCalls)
+	}
+}
+
+func TestPlanForceRedownloadsAndReinstallsCores(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	// Pre-populate a stale binary to prove force overwrites.
+	os.MkdirAll(filepath.Join(home, ".local", "bin"), 0o755)
+	bp := filepath.Join(home, ".local", "bin", "arduino-cli")
+	os.WriteFile(bp, []byte("stale"), 0o755)
+
+	archive := makeTarGz(t, map[string][]byte{"arduino-cli": []byte("#!/bin/sh\nfresh\n")})
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		data, _ := os.ReadFile(archive)
+		w.Write(data)
+	}))
+	defer srv.Close()
+
+	r := &fakeRunner{coreListOut: []byte("arduino:avr\nesp32:esp32\n")}
+	m := New(config.ArduinoCLIConfig{
+		Version: "1.0.0",
+		URL:     srv.URL + "/arduino-cli.tgz",
+		Cores:   []string{"arduino:avr", "esp32:esp32"},
+	}, r)
+
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec %q: %v", a.Description, err)
+		}
+	}
+
+	// Binary got overwritten with fresh payload.
+	got, _ := os.ReadFile(bp)
+	if string(got) == "stale" {
+		t.Fatalf("binary not overwritten by force")
+	}
+
+	// update-index and both `core install` calls fired.
+	sawUpdate := false
+	installed := map[string]bool{}
+	for _, c := range r.runCalls {
+		if filepath.Base(c[0]) == "arduino-cli" && len(c) >= 3 && c[1] == "core" && c[2] == "update-index" {
+			sawUpdate = true
+		}
+		if filepath.Base(c[0]) == "arduino-cli" && len(c) >= 4 && c[1] == "core" && c[2] == "install" {
+			installed[c[3]] = true
+		}
+	}
+	if !sawUpdate {
+		t.Errorf("no core update-index call; calls=%v", r.runCalls)
+	}
+	if !installed["arduino:avr"] || !installed["esp32:esp32"] {
+		t.Errorf("expected both cores force-installed; got=%v calls=%v", installed, r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/fonts/fonts.go

@@ -0,0 +1,101 @@
+// Package fonts installs AUR fonts via the yay helper.
+package fonts
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	fonts []string
+	pm    platform.PackageManager
+	aur   platform.AURHelper
+}
+
+func New(fonts []string, pm platform.PackageManager, aur platform.AURHelper) Module {
+	return Module{fonts: fonts, pm: pm, aur: aur}
+}
+
+type state struct{ Missing []string }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "fonts", Name: "Nerd fonts", Description: "Install AUR nerd fonts."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []string
+	for _, f := range m.fonts {
+		ok, err := m.pm.IsInstalled(ctx, f)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			missing = append(missing, f)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	missing := append([]string{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{
+		{
+			Description: "ensure yay installed",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.EnsureInstalled(ctx) },
+		},
+		{
+			Description: "yay install " + strings.Join(missing, ", "),
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.Install(ctx, missing) },
+		},
+	}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if miss := st.(state).Missing; len(miss) > 0 {
+		return fmt.Errorf("fonts still missing: %v", miss)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.fonts) == 0 {
+		return module.Plan{}, nil
+	}
+	fonts := append([]string{}, m.fonts...)
+	return module.Plan{Actions: []module.Action{
+		{
+			Description: "ensure yay installed",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.EnsureInstalled(ctx) },
+		},
+		{
+			Description: "yay -S (force) " + strings.Join(fonts, ", "),
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.Reinstall(ctx, fonts) },
+		},
+	}}, nil
+}

internal/modules/fonts/fonts_test.go

@@ -0,0 +1,99 @@
+package fonts
+
+import (
+	"context"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte("ok"), nil
+		}
+		return nil, errOne
+	}
+	return nil, nil
+}
+
+type eo struct{}
+
+func (eo) Error() string { return "exit 1" }
+
+var errOne = eo{}
+
+type nop struct{}
+
+func (nop) Progress(string, int, int, string) {}
+func (nop) Log(string, string)                {}
+
+func TestFontsPlanApplyUsesYay(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yay": true}}
+	m := New([]string{"ttf-jetbrains-mono-nerd"}, platform.NewPacman(r), platform.NewYay(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+	sawYay := false
+	for _, c := range r.runCalls {
+		if len(c) >= 2 && c[0] == "yay" && c[1] == "-S" {
+			sawYay = true
+		}
+	}
+	if !sawYay {
+		t.Fatalf("no yay install; calls=%v", r.runCalls)
+	}
+}
+
+func TestFontsDetectPresentNoActions(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yay": true, "ttf-jetbrains-mono-nerd": true}}
+	m := New([]string{"ttf-jetbrains-mono-nerd"}, platform.NewPacman(r), platform.NewYay(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if !p.IsEmpty() {
+		t.Fatal("want empty plan when already installed")
+	}
+}
+
+func TestPlanForceReinstallsAllFonts(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yay": true, "ttf-jetbrains-mono-nerd": true}}
+	m := New([]string{"ttf-jetbrains-mono-nerd"}, platform.NewPacman(r), platform.NewYay(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		// yay -S --noconfirm ... (no --needed)
+		if len(c) >= 3 && c[0] == "yay" && c[1] == "-S" && c[2] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no yay reinstall (-S --noconfirm, no --needed) call; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/gittools/gittools.go

@@ -0,0 +1,86 @@
+// Package gittools installs a declarative list of pacman packages.
+package gittools
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	pkgs []string
+	pm   platform.PackageManager
+}
+
+func New(pkgs []string, pm platform.PackageManager) Module {
+	return Module{pkgs: pkgs, pm: pm}
+}
+
+type state struct{ Missing []string }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "gittools", Name: "Git tools", Description: "Install lazygit."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []string
+	for _, p := range m.pkgs {
+		ok, err := m.pm.IsInstalled(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			missing = append(missing, p)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	missing := append([]string{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman install " + strings.Join(missing, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, missing) },
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if missing := st.(state).Missing; len(missing) > 0 {
+		return fmt.Errorf("packages not installed after apply: %v", missing)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.pkgs) == 0 {
+		return module.Plan{}, nil
+	}
+	pkgs := append([]string{}, m.pkgs...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+	}}}, nil
+}

internal/modules/gittools/gittools_test.go

@@ -0,0 +1,139 @@
+package gittools
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool // key: pkg name
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte(args[1] + " 1.0-1\n"), nil
+		}
+		return nil, errExitOne
+	}
+	return nil, nil
+}
+
+type exitOneErr struct{}
+
+func (exitOneErr) Error() string { return "exit status 1" }
+
+var errExitOne = exitOneErr{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestDetectAbsent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"lazygit"}, platform.NewPacman(r))
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if len(s.Missing) != 1 {
+		t.Fatalf("want 1 missing, got %v", s.Missing)
+	}
+}
+
+func TestDetectPresent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"lazygit": true}}
+	m := New([]string{"lazygit"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	if len(st.(state).Missing) != 0 {
+		t.Fatalf("want 0 missing, got %v", st.(state).Missing)
+	}
+}
+
+func TestPlanAbsentEmitsInstallAction(t *testing.T) {
+	m := New([]string{"lazygit"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: []string{"lazygit"}})
+	if len(p.Actions) != 1 {
+		t.Fatalf("want 1 action, got %d", len(p.Actions))
+	}
+	if !strings.Contains(p.Actions[0].Description, "lazygit") {
+		t.Fatalf("desc: %s", p.Actions[0].Description)
+	}
+}
+
+func TestPlanPresentEmpty(t *testing.T) {
+	m := New([]string{"lazygit"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: nil})
+	if !p.IsEmpty() {
+		t.Fatal("want empty plan")
+	}
+}
+
+func TestApplyShellsOut(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"lazygit"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	sawInstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" {
+			sawInstall = true
+		}
+	}
+	if !sawInstall {
+		t.Fatalf("no pacman install call; calls=%v", r.runCalls)
+	}
+}
+
+func TestVerifyAfterApply(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"lazygit": true}}
+	m := New([]string{"lazygit"}, platform.NewPacman(r))
+	if err := m.Verify(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPlanForceReinstallsAllPackages(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"lazygit": true}}
+	m := New([]string{"lazygit"}, platform.NewPacman(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty even when packages are installed")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall (-S --noconfirm, no --needed) call; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/hello/hello.go

@@ -0,0 +1,115 @@
+// Package hello is a toy module that writes a marker file. It exists to
+// validate the engine end-to-end before real modules arrive in Plan 3.
+package hello
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+const defaultRelPath = ".cache/archduino/hello.ok"
+const markerContent = "archduino-hello\n"
+
+// Module is the exported module value. Path is overridable for tests.
+type Module struct {
+	Path string // absolute path; if empty, ~/.cache/archduino/hello.ok is used
+}
+
+func (m Module) resolve() (string, error) {
+	if m.Path != "" {
+		return m.Path, nil
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(home, defaultRelPath), nil
+}
+
+func (Module) Meta() module.Meta {
+	return module.Meta{
+		ID:          "hello",
+		Name:        "Hello",
+		Description: "Toy module that writes a marker file (engine smoke test).",
+	}
+}
+
+type state struct{ Present bool }
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	path, err := m.resolve()
+	if err != nil {
+		return nil, err
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return state{Present: false}, nil
+		}
+		return nil, err
+	}
+	return state{Present: string(data) == markerContent}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if s.Present {
+		return module.Plan{}, nil
+	}
+	path, err := m.resolve()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	return module.Plan{Actions: []module.Action{{
+		Description: "write marker " + path,
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+				return err
+			}
+			return os.WriteFile(path, []byte(markerContent), 0o644)
+		},
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if !st.(state).Present {
+		return fmt.Errorf("hello: marker not present after apply")
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	path, err := m.resolve()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	return module.Plan{Actions: []module.Action{{
+		Description: "hello force reapply (rewrite marker " + path + ")",
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+				return err
+			}
+			return os.WriteFile(path, []byte(markerContent), 0o644)
+		},
+	}}}, nil
+}

internal/modules/hello/hello_test.go

@@ -0,0 +1,85 @@
+package hello
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/engine"
+)
+
+func TestHelloFullLifecycle(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "hello.ok")
+	m := Module{Path: path}
+	ctx := context.Background()
+
+	st, err := m.Detect(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if st.(state).Present {
+		t.Fatal("marker should be absent on fresh tmpdir")
+	}
+
+	plan, err := m.Plan(ctx, st)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("plan should have one action")
+	}
+
+	if err := m.Apply(ctx, plan, engine.NewBufferedReporter()); err != nil {
+		t.Fatal(err)
+	}
+	if err := m.Verify(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	st2, _ := m.Detect(ctx)
+	if !st2.(state).Present {
+		t.Fatal("marker should be present after apply")
+	}
+
+	plan2, _ := m.Plan(ctx, st2)
+	if !plan2.IsEmpty() {
+		t.Fatal("second plan should be empty (idempotent)")
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(data) != markerContent {
+		t.Fatalf("content = %q", data)
+	}
+}
+
+func TestHelloPlanForceNonEmpty(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "hello.ok")
+	m := Module{Path: path}
+	// Even after marker is present, force plan must run.
+	if err := os.WriteFile(path, []byte(markerContent), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(data) != markerContent {
+		t.Fatalf("content after force = %q", data)
+	}
+}

internal/modules/neovim/assets/arduino.lua

@@ -0,0 +1,10 @@
+return {
+  {
+    "stevearc/vim-arduino",
+    ft = { "arduino", "cpp", "c" },
+    config = function()
+      vim.g.arduino_use_cli = 1
+      vim.g.arduino_cli_path = "arduino-cli"
+    end,
+  },
+}

internal/modules/neovim/assets/chadrc.lua.tmpl

@@ -0,0 +1,8 @@
+---@type ChadrcConfig
+local M = {}
+
+M.base46 = {
+  theme = "{{.NvChadTheme}}",
+}
+
+return M

internal/modules/neovim/assets/clangd.lua

@@ -0,0 +1,10 @@
+return {
+  cmd = {
+    "clangd",
+    "--background-index",
+    "--clang-tidy",
+    "--header-insertion=iwyu",
+    "--completion-style=detailed",
+  },
+  filetypes = { "c", "cpp", "objc", "objcpp", "cuda", "arduino" },
+}

internal/modules/neovim/assets/dap.lua

@@ -0,0 +1,57 @@
+return {
+  {
+    "mfussenegger/nvim-dap",
+    keys = { "<leader>d" },
+    config = function()
+      local dap = require("dap")
+
+      -- GDB remote adapter (connects to Renode's GDB server)
+      dap.adapters.gdb_remote = {
+        type = "executable",
+        command = vim.fn.executable("arm-none-eabi-gdb") == 1
+          and "arm-none-eabi-gdb"
+          or "gdb-multiarch",
+        args = { "-i", "dap" },
+      }
+
+      -- Default debug configurations for Arduino/embedded
+      dap.configurations.c = {
+        {
+          name = "Attach to Renode (GDB :3333)",
+          type = "gdb_remote",
+          request = "attach",
+          target = "localhost:3333",
+          cwd = "${workspaceFolder}",
+          program = function()
+            return vim.fn.input("ELF path: ", vim.fn.getcwd() .. "/build/", "file")
+          end,
+        },
+      }
+      dap.configurations.cpp = dap.configurations.c
+      dap.configurations.arduino = dap.configurations.c
+
+      -- Breakpoint signs
+      vim.fn.sign_define("DapBreakpoint", { text = "●", texthl = "DiagnosticError" })
+      vim.fn.sign_define("DapStopped", { text = "▶", texthl = "DiagnosticOk", linehl = "DiffAdd" })
+    end,
+  },
+  {
+    "rcarriga/nvim-dap-ui",
+    dependencies = { "mfussenegger/nvim-dap", "nvim-neotest/nvim-nio" },
+    keys = { "<leader>du" },
+    config = function()
+      local dapui = require("dapui")
+      dapui.setup()
+
+      -- Auto open/close UI on debug sessions
+      local dap = require("dap")
+      dap.listeners.after.event_initialized["dapui_config"] = function() dapui.open() end
+      dap.listeners.before.event_terminated["dapui_config"] = function() dapui.close() end
+      dap.listeners.before.event_exited["dapui_config"] = function() dapui.close() end
+    end,
+  },
+  {
+    "nvim-neotest/nvim-nio",
+    lazy = true,
+  },
+}

internal/modules/neovim/assets/lspconfig.lua

@@ -0,0 +1,2 @@
+vim.lsp.enable("clangd")
+return {}

internal/modules/neovim/assets/mappings.lua

@@ -0,0 +1,20 @@
+require "nvchad.mappings"
+
+local map = vim.keymap.set
+
+map("n", "<leader>ac", "<cmd>ArduinoChooseBoard<cr>", { desc = "Arduino Choose Board" })
+map("n", "<leader>ap", "<cmd>ArduinoChoosePort<cr>", { desc = "Arduino Choose Port" })
+map("n", "<leader>av", "<cmd>ArduinoVerify<cr>", { desc = "Arduino Verify (compile)" })
+map("n", "<leader>au", "<cmd>ArduinoUpload<cr>", { desc = "Arduino Upload" })
+map("n", "<leader>as", "<cmd>ArduinoSerial<cr>", { desc = "Arduino Serial Monitor" })
+map("n", "<leader>ai", "<cmd>ArduinoInfo<cr>", { desc = "Arduino Board Info" })
+map("n", "<leader>aw", "<cmd>!wokwi-cli .<cr>", { desc = "Arduino Wokwi Simulate" })
+
+-- Debug (DAP)
+map("n", "<leader>ds", function() require("dap").continue() end, { desc = "Debug Start/Continue" })
+map("n", "<leader>db", function() require("dap").toggle_breakpoint() end, { desc = "Debug Toggle Breakpoint" })
+map("n", "<leader>dn", function() require("dap").step_over() end, { desc = "Debug Step Over" })
+map("n", "<leader>di", function() require("dap").step_into() end, { desc = "Debug Step Into" })
+map("n", "<leader>do", function() require("dap").step_out() end, { desc = "Debug Step Out" })
+map("n", "<leader>dx", function() require("dap").terminate() end, { desc = "Debug Terminate" })
+map("n", "<leader>du", function() require("dapui").toggle() end, { desc = "Debug UI Toggle" })

internal/modules/neovim/neovim.go

@@ -0,0 +1,575 @@
+// Package neovim installs Neovim via pacman, clones the NvChad starter,
+// backs up any non-NvChad config, strips the starter's nvim-lspconfig
+// block, and writes Archduino's Lua asset files.
+package neovim
+
+import (
+	"bytes"
+	"context"
+	"embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+	"time"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/theming"
+)
+
+//go:embed assets/*
+var assets embed.FS
+
+// Register WriteChadrc with the theming package so theming.Apply can
+// rewrite chadrc.lua on theme changes without importing this package
+// (which would be a cycle: neovim imports theming).
+func init() {
+	theming.ChadrcWriter = WriteChadrc
+}
+
+// assetMap lists each asset and its destination under ~/.config/nvim.
+// Order matters: Detect iterates in this order and Apply writes in this order.
+var assetMap = []struct {
+	SrcPath string // under assets/
+	DstRel  string // under ~/.config/nvim/
+}{
+	{"assets/arduino.lua", "lua/plugins/arduino.lua"},
+	{"assets/dap.lua", "lua/plugins/dap.lua"},
+	{"assets/lspconfig.lua", "lua/plugins/lspconfig.lua"},
+	{"assets/mappings.lua", "lua/mappings.lua"},
+	{"assets/clangd.lua", "lsp/clangd.lua"},
+}
+
+// Module installs and configures Neovim + NvChad for Archduino.
+type Module struct {
+	cfg     config.NeovimConfig
+	themeID string
+	pm      platform.PackageManager
+	git     platform.GitClient
+}
+
+// New constructs a Neovim Module.
+func New(cfg config.NeovimConfig, themeID string, pm platform.PackageManager, git platform.GitClient) Module {
+	return Module{cfg: cfg, themeID: themeID, pm: pm, git: git}
+}
+
+type state struct {
+	NvimInstalled   bool
+	ConfigDirExists bool
+	ChadrcPresent   bool
+	BackupNeeded    bool
+	BackupSource    string
+	StarterCloned   bool
+	MissingAssets   []string
+	ChadrcDrift     bool
+	LspconfigBlock  bool
+	StarterLspFile  bool
+	ThemeName       string
+	RenderedChadrc  []byte
+}
+
+// Meta returns the module metadata.
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "neovim", Name: "Neovim + NvChad", Description: "Install Neovim and configure NvChad with Archduino plugins."}
+}
+
+func nvimCfg() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".config", "nvim"), nil
+}
+
+func (m Module) resolvedTheme() string {
+	if t, ok := theming.Get(m.themeID); ok {
+		return t.NvChadTheme
+	}
+	return theming.Default().NvChadTheme
+}
+
+// WriteChadrc renders chadrc.lua for the given NvChad theme name and writes
+// it to ~/.config/nvim/lua/chadrc.lua. If the file does not already exist
+// and the surrounding nvim config dir does not exist, the function returns
+// nil without writing anything (the user hasn't installed neovim yet).
+//
+// Exported so the theming package can re-render chadrc on theme switches
+// without re-running the full Module pipeline.
+func WriteChadrc(nvChadThemeName string) error {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return err
+	}
+	cfg := filepath.Join(home, ".config", "nvim")
+	chadrcPath := filepath.Join(cfg, "lua", "chadrc.lua")
+
+	// If chadrc doesn't exist, only write when the parent dir exists. A
+	// fresh system where nvim was never installed should be a no-op.
+	if _, err := os.Stat(chadrcPath); err != nil {
+		if _, err := os.Stat(cfg); err != nil {
+			return nil
+		}
+	}
+
+	tmplBytes, err := assets.ReadFile("assets/chadrc.lua.tmpl")
+	if err != nil {
+		return err
+	}
+	tmpl, err := template.New("chadrc").Parse(string(tmplBytes))
+	if err != nil {
+		return err
+	}
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, struct{ NvChadTheme string }{NvChadTheme: nvChadThemeName}); err != nil {
+		return err
+	}
+	return platform.WriteUserFile(chadrcPath, buf.Bytes(), 0o644)
+}
+
+func (m Module) renderChadrc() ([]byte, error) {
+	tmplBytes, err := assets.ReadFile("assets/chadrc.lua.tmpl")
+	if err != nil {
+		return nil, err
+	}
+	tmpl, err := template.New("chadrc").Parse(string(tmplBytes))
+	if err != nil {
+		return nil, err
+	}
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, struct{ NvChadTheme string }{NvChadTheme: m.resolvedTheme()}); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// Detect inspects the filesystem and returns the current state.
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	cfg, err := nvimCfg()
+	if err != nil {
+		return nil, err
+	}
+	var s state
+	s.ThemeName = m.resolvedTheme()
+	if m.pm != nil {
+		ok, err := m.pm.IsInstalled(ctx, "neovim")
+		if err != nil {
+			return nil, err
+		}
+		s.NvimInstalled = ok
+	}
+
+	rendered, err := m.renderChadrc()
+	if err != nil {
+		return nil, err
+	}
+	s.RenderedChadrc = rendered
+
+	if fi, err := os.Stat(cfg); err == nil && fi.IsDir() {
+		s.ConfigDirExists = true
+		if _, err := os.Stat(filepath.Join(cfg, "lua", "chadrc.lua")); err == nil {
+			s.ChadrcPresent = true
+		}
+		if _, err := os.Stat(filepath.Join(cfg, "lua")); err == nil && !s.ChadrcPresent {
+			s.BackupNeeded = true
+			s.BackupSource = cfg
+		}
+	}
+	if _, err := os.Stat(filepath.Join(cfg, "lua", "plugins", "init.lua")); err == nil {
+		s.StarterCloned = true
+		data, _ := os.ReadFile(filepath.Join(cfg, "lua", "plugins", "init.lua"))
+		if bytes.Contains(data, []byte("nvim-lspconfig")) {
+			s.LspconfigBlock = true
+		}
+	}
+	if _, err := os.Stat(filepath.Join(cfg, "lua", "configs", "lspconfig.lua")); err == nil {
+		s.StarterLspFile = true
+	}
+
+	if cur, err := os.ReadFile(filepath.Join(cfg, "lua", "chadrc.lua")); err == nil {
+		if !bytes.Equal(cur, rendered) {
+			s.ChadrcDrift = true
+		}
+	}
+
+	for _, a := range assetMap {
+		want, _ := assets.ReadFile(a.SrcPath)
+		got, err := os.ReadFile(filepath.Join(cfg, a.DstRel))
+		if err != nil || !bytes.Equal(got, want) {
+			s.MissingAssets = append(s.MissingAssets, a.DstRel)
+		}
+	}
+	return s, nil
+}
+
+// stripLspconfigBlock removes the plugin-table entry that references
+// "neovim/nvim-lspconfig" from the NvChad starter's init.lua. It walks the
+// source line-by-line: find the marker line, scan backward for the opening
+// `{` of that entry, then scan forward counting braces until the matching
+// `}` (plus trailing `,` if present). Robust against nested tables inside
+// the entry (e.g. `opts = {}`) that defeat single-level regexes.
+func stripLspconfigBlock(src []byte) []byte {
+	lines := strings.Split(string(src), "\n")
+	markerIdx := -1
+	for i, l := range lines {
+		if strings.Contains(l, "neovim/nvim-lspconfig") {
+			markerIdx = i
+			break
+		}
+	}
+	if markerIdx == -1 {
+		return src
+	}
+
+	// Scan backward for the opening `{` that begins the plugin entry.
+	// We track braces relative to the marker line so nested tables on
+	// earlier lines don't confuse the search: we want the first `{`
+	// whose pair would enclose the marker.
+	startLine := -1
+	depth := 0
+	for i := markerIdx; i >= 0; i-- {
+		// Count braces on this line from right to left.
+		for j := len(lines[i]) - 1; j >= 0; j-- {
+			c := lines[i][j]
+			if c == '}' {
+				depth++
+			} else if c == '{' {
+				if depth == 0 {
+					startLine = i
+					// break out of both loops
+					i = -1
+					break
+				}
+				depth--
+			}
+		}
+	}
+	if startLine == -1 {
+		return src
+	}
+
+	// Scan forward from markerIdx for the matching `}`.
+	endLine := -1
+	depth = 1 // we're already inside the `{` at startLine
+	// Start just after the opening `{` on startLine.
+	for i := startLine; i < len(lines); i++ {
+		start := 0
+		if i == startLine {
+			// skip past the first `{` on this line
+			idx := strings.Index(lines[i], "{")
+			if idx >= 0 {
+				start = idx + 1
+			}
+		}
+		for j := start; j < len(lines[i]); j++ {
+			c := lines[i][j]
+			if c == '{' {
+				depth++
+			} else if c == '}' {
+				depth--
+				if depth == 0 {
+					endLine = i
+					break
+				}
+			}
+		}
+		if endLine != -1 {
+			break
+		}
+	}
+	if endLine == -1 {
+		return src
+	}
+
+	// Include an optional trailing comma and whitespace-only lines after endLine.
+	cutEnd := endLine
+	// If the `}` line also has a trailing `,`, that's fine; keep the line as-is
+	// but drop it. If the endLine text after the closing `}` is just `,` or
+	// `,` + whitespace, keep cutEnd = endLine. Otherwise also keep cutEnd.
+	// Skip a single blank line after the block to avoid leaving a stray gap.
+	if cutEnd+1 < len(lines) && strings.TrimSpace(lines[cutEnd+1]) == "" {
+		cutEnd++
+	}
+
+	out := make([]string, 0, len(lines)-(cutEnd-startLine+1))
+	out = append(out, lines[:startLine]...)
+	out = append(out, lines[cutEnd+1:]...)
+	return []byte(strings.Join(out, "\n"))
+}
+
+// Plan computes the idempotent set of actions to converge to desired state.
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	cfg, err := nvimCfg()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	var actions []module.Action
+
+	if !s.NvimInstalled && m.pm != nil {
+		actions = append(actions, module.Action{
+			Description: "pacman install neovim",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, []string{"neovim"}) },
+		})
+	}
+
+	if s.BackupNeeded {
+		src := s.BackupSource
+		actions = append(actions, module.Action{
+			Description: "back up existing non-NvChad config",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				ts := time.Now().UTC().Format("20060102T150405Z")
+				return os.Rename(src, src+".bak."+ts)
+			},
+		})
+	}
+
+	if !s.StarterCloned || s.BackupNeeded {
+		repo := m.cfg.NvChadStarterRepo
+		actions = append(actions, module.Action{
+			Description: "clone NvChad starter",
+			Kind:        module.ActionGitClone,
+			Exec: func(ctx context.Context) error {
+				if err := os.MkdirAll(filepath.Dir(cfg), 0o755); err != nil {
+					return err
+				}
+				if err := m.git.Clone(ctx, repo, cfg); err != nil {
+					return err
+				}
+				return os.RemoveAll(filepath.Join(cfg, ".git"))
+			},
+		})
+	}
+
+	if s.LspconfigBlock || !s.StarterCloned || s.BackupNeeded {
+		actions = append(actions, module.Action{
+			Description: "strip nvim-lspconfig block from starter init.lua",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				p := filepath.Join(cfg, "lua", "plugins", "init.lua")
+				data, err := os.ReadFile(p)
+				if err != nil {
+					return err
+				}
+				return platform.WriteUserFile(p, stripLspconfigBlock(data), 0o644)
+			},
+		})
+	}
+
+	if s.StarterLspFile || !s.StarterCloned || s.BackupNeeded {
+		actions = append(actions, module.Action{
+			Description: "remove starter lspconfig.lua",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				err := os.Remove(filepath.Join(cfg, "lua", "configs", "lspconfig.lua"))
+				if err != nil && !os.IsNotExist(err) {
+					return err
+				}
+				return nil
+			},
+		})
+	}
+
+	if s.ChadrcDrift || !s.ChadrcPresent || s.BackupNeeded {
+		rendered := append([]byte{}, s.RenderedChadrc...)
+		actions = append(actions, module.Action{
+			Description: "write chadrc.lua with theme " + s.ThemeName,
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				return platform.WriteUserFile(filepath.Join(cfg, "lua", "chadrc.lua"), rendered, 0o644)
+			},
+		})
+	}
+
+	for _, dst := range s.MissingAssets {
+		dst := dst
+		actions = append(actions, module.Action{
+			Description: "write asset " + dst,
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				var src string
+				for _, a := range assetMap {
+					if a.DstRel == dst {
+						src = a.SrcPath
+						break
+					}
+				}
+				data, err := assets.ReadFile(src)
+				if err != nil {
+					return err
+				}
+				return platform.WriteUserFile(filepath.Join(cfg, dst), data, 0o644)
+			},
+		})
+	}
+
+	if len(actions) > 0 {
+		actions = append(actions, module.Action{
+			Description: "clear NvChad base46 theme cache",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				home, _ := os.UserHomeDir()
+				_ = os.RemoveAll(filepath.Join(home, ".local", "share", "nvim", "lazy", "base46", "lua", "base46", "themes"))
+				_ = os.RemoveAll(filepath.Join(home, ".cache", "nvim", "base46"))
+				return nil
+			},
+		})
+	}
+
+	return module.Plan{Actions: actions}, nil
+}
+
+// Apply executes the planned actions in order.
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Verify re-Detects and returns an error if state is not converged.
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	s := st.(state)
+	if !s.NvimInstalled {
+		return fmt.Errorf("neovim not installed")
+	}
+	if !s.ChadrcPresent {
+		return fmt.Errorf("chadrc.lua missing")
+	}
+	if s.ChadrcDrift {
+		return fmt.Errorf("chadrc.lua content drifted")
+	}
+	if len(s.MissingAssets) > 0 {
+		return fmt.Errorf("missing assets: %v", s.MissingAssets)
+	}
+	if s.LspconfigBlock {
+		return fmt.Errorf("nvim-lspconfig block not stripped")
+	}
+	if s.StarterLspFile {
+		return fmt.Errorf("starter lspconfig.lua still present")
+	}
+	return nil
+}
+
+// PlanForce rewrites chadrc.lua and reinstalls packages but does NOT
+// delete an existing NvChad clone, to preserve any user modifications.
+// If NvChad is missing, it's cloned fresh.
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	cfg, err := nvimCfg()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	rendered, err := m.renderChadrc()
+	if err != nil {
+		return module.Plan{}, err
+	}
+
+	var actions []module.Action
+
+	if m.pm != nil {
+		actions = append(actions, module.Action{
+			Description: "pacman -S (force) neovim",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, []string{"neovim"}) },
+		})
+	}
+
+	// Clone NvChad only if absent; preserve any user modifications otherwise.
+	repo := m.cfg.NvChadStarterRepo
+	actions = append(actions, module.Action{
+		Description: "ensure NvChad starter cloned (skip if present)",
+		Kind:        module.ActionGitClone,
+		Exec: func(ctx context.Context) error {
+			if _, err := os.Stat(filepath.Join(cfg, "lua", "plugins", "init.lua")); err == nil {
+				return nil
+			}
+			if err := os.MkdirAll(filepath.Dir(cfg), 0o755); err != nil {
+				return err
+			}
+			if err := m.git.Clone(ctx, repo, cfg); err != nil {
+				return err
+			}
+			return os.RemoveAll(filepath.Join(cfg, ".git"))
+		},
+	})
+
+	actions = append(actions, module.Action{
+		Description: "strip nvim-lspconfig block from starter init.lua (force)",
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			p := filepath.Join(cfg, "lua", "plugins", "init.lua")
+			data, err := os.ReadFile(p)
+			if err != nil {
+				if os.IsNotExist(err) {
+					return nil
+				}
+				return err
+			}
+			return platform.WriteUserFile(p, stripLspconfigBlock(data), 0o644)
+		},
+	})
+
+	actions = append(actions, module.Action{
+		Description: "remove starter lspconfig.lua (force)",
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			err := os.Remove(filepath.Join(cfg, "lua", "configs", "lspconfig.lua"))
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			return nil
+		},
+	})
+
+	renderedCopy := append([]byte{}, rendered...)
+	themeName := m.resolvedTheme()
+	actions = append(actions, module.Action{
+		Description: "rewrite chadrc.lua with theme " + themeName + " (force)",
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			if err := os.MkdirAll(filepath.Join(cfg, "lua"), 0o755); err != nil {
+				return err
+			}
+			return platform.WriteUserFile(filepath.Join(cfg, "lua", "chadrc.lua"), renderedCopy, 0o644)
+		},
+	})
+
+	for _, a := range assetMap {
+		a := a
+		actions = append(actions, module.Action{
+			Description: "rewrite asset " + a.DstRel + " (force)",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				data, err := assets.ReadFile(a.SrcPath)
+				if err != nil {
+					return err
+				}
+				return platform.WriteUserFile(filepath.Join(cfg, a.DstRel), data, 0o644)
+			},
+		})
+	}
+
+	actions = append(actions, module.Action{
+		Description: "clear NvChad base46 theme cache (force)",
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			home, _ := os.UserHomeDir()
+			_ = os.RemoveAll(filepath.Join(home, ".local", "share", "nvim", "lazy", "base46", "lua", "base46", "themes"))
+			_ = os.RemoveAll(filepath.Join(home, ".cache", "nvim", "base46"))
+			return nil
+		},
+	})
+
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/neovim/neovim_test.go

@@ -0,0 +1,299 @@
+package neovim
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls, outCalls [][]string
+	installed          map[string]bool
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	if name == "git" && len(args) >= 1 && args[0] == "clone" {
+		dest := args[len(args)-1]
+		os.MkdirAll(filepath.Join(dest, "lua", "plugins"), 0o755)
+		os.WriteFile(filepath.Join(dest, "lua", "plugins", "init.lua"),
+			[]byte("return {\n  \"neovim/nvim-lspconfig\",\n  opts = {},\n},\n{\n  \"other\",\n},\n"),
+			0o644)
+		os.MkdirAll(filepath.Join(dest, "lua", "configs"), 0o755)
+		os.WriteFile(filepath.Join(dest, "lua", "configs", "lspconfig.lua"), []byte("stub"), 0o644)
+	}
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte("ok"), nil
+		}
+		return nil, errExit1
+	}
+	return nil, nil
+}
+
+type exitOne struct{}
+
+func (exitOne) Error() string { return "exit 1" }
+
+var errExit1 = exitOne{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestDetectFreshSystem(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "gruvbox", platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if s.NvimInstalled {
+		t.Error("nvim should be absent")
+	}
+	if s.ChadrcPresent {
+		t.Error("chadrc should be absent")
+	}
+	if s.BackupNeeded {
+		t.Error("no backup on empty system")
+	}
+}
+
+func TestDetectNonNvChadTriggersBackup(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.MkdirAll(filepath.Join(home, ".config", "nvim", "lua"), 0o755)
+	os.WriteFile(filepath.Join(home, ".config", "nvim", "lua", "plugins.lua"), []byte("-- lazyvim"), 0o644)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "gruvbox", platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	if !st.(state).BackupNeeded {
+		t.Fatal("expected BackupNeeded=true")
+	}
+}
+
+func TestPlanApplyInstallsEverything(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "dracula", platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if len(p.Actions) == 0 {
+		t.Fatal("empty plan")
+	}
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+
+	sawPacman, sawClone := false, false
+	for _, c := range r.runCalls {
+		if len(c) >= 3 && c[0] == "sudo" && c[1] == "pacman" {
+			sawPacman = true
+		}
+		if c[0] == "git" && len(c) >= 2 && c[1] == "clone" {
+			sawClone = true
+		}
+	}
+	if !sawPacman || !sawClone {
+		t.Fatalf("missing steps; calls=%v", r.runCalls)
+	}
+
+	nvimCfg := filepath.Join(home, ".config", "nvim")
+	chadrc, err := os.ReadFile(filepath.Join(nvimCfg, "lua", "chadrc.lua"))
+	if err != nil {
+		t.Fatalf("chadrc missing: %v", err)
+	}
+	if !strings.Contains(string(chadrc), `theme = "dracula"`) {
+		t.Fatalf("chadrc theme not applied: %s", chadrc)
+	}
+
+	initLua, _ := os.ReadFile(filepath.Join(nvimCfg, "lua", "plugins", "init.lua"))
+	if strings.Contains(string(initLua), "nvim-lspconfig") {
+		t.Fatalf("nvim-lspconfig not stripped: %s", initLua)
+	}
+
+	if _, err := os.Stat(filepath.Join(nvimCfg, "lua", "configs", "lspconfig.lua")); !os.IsNotExist(err) {
+		t.Fatal("starter lspconfig.lua should be removed")
+	}
+
+	for _, name := range []string{"arduino.lua", "dap.lua"} {
+		if _, err := os.Stat(filepath.Join(nvimCfg, "lua", "plugins", name)); err != nil {
+			t.Errorf("asset %s missing: %v", name, err)
+		}
+	}
+	if _, err := os.Stat(filepath.Join(nvimCfg, "lua", "mappings.lua")); err != nil {
+		t.Errorf("mappings.lua missing: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(nvimCfg, "lsp", "clangd.lua")); err != nil {
+		t.Errorf("clangd.lua missing: %v", err)
+	}
+}
+
+func TestPlanAfterApplyIsEmpty(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{"neovim": true}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "gruvbox", platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	_ = m.Apply(context.Background(), p, nopReporter{})
+	st2, _ := m.Detect(context.Background())
+	p2, _ := m.Plan(context.Background(), st2)
+	if !p2.IsEmpty() {
+		t.Fatalf("second plan not empty: %+v", p2.Actions)
+	}
+}
+
+func TestUnknownThemeFallsBackToDefault(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{"neovim": true}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "does-not-exist", platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	chadrc, _ := os.ReadFile(filepath.Join(home, ".config", "nvim", "lua", "chadrc.lua"))
+	// Unknown theme IDs fall back to theming.Default(), which is gruvbox.
+	if !strings.Contains(string(chadrc), `theme = "gruvbox"`) {
+		t.Fatalf("fallback theme not applied: %s", chadrc)
+	}
+}
+
+func TestWriteChadrcWritesFile(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	cfg := filepath.Join(home, ".config", "nvim")
+	if err := os.MkdirAll(cfg, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := WriteChadrc("dracula"); err != nil {
+		t.Fatal(err)
+	}
+	data, err := os.ReadFile(filepath.Join(cfg, "lua", "chadrc.lua"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(data), `theme = "dracula"`) {
+		t.Fatalf("theme not applied: %s", data)
+	}
+}
+
+func TestWriteChadrcNoopWithoutConfigDir(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	if err := WriteChadrc("gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(filepath.Join(home, ".config", "nvim", "lua", "chadrc.lua")); !os.IsNotExist(err) {
+		t.Fatal("chadrc should not be created on a bare system")
+	}
+}
+
+func TestPlanForceReinstallsAndRewrites(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	// Pre-populate an "installed" NvChad clone with a local user tweak so we
+	// can verify PlanForce does NOT wipe the clone.
+	cfg := filepath.Join(home, ".config", "nvim")
+	os.MkdirAll(filepath.Join(cfg, "lua", "plugins"), 0o755)
+	os.WriteFile(filepath.Join(cfg, "lua", "plugins", "init.lua"),
+		[]byte("return {\n  \"other\",\n},\n"), 0o644)
+	userTweak := filepath.Join(cfg, "lua", "user_tweak.lua")
+	os.WriteFile(userTweak, []byte("-- my custom stuff"), 0o644)
+
+	r := &fakeRunner{installed: map[string]bool{"neovim": true}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "dracula", platform.NewPacman(r), platform.GitClient{Runner: r})
+
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec %q: %v", a.Description, err)
+		}
+	}
+
+	// User tweak must survive.
+	if _, err := os.Stat(userTweak); err != nil {
+		t.Fatalf("PlanForce wiped user NvChad modification: %v", err)
+	}
+	// No `git clone` call because starter init.lua was already present.
+	for _, c := range r.runCalls {
+		if c[0] == "git" && len(c) >= 2 && c[1] == "clone" {
+			t.Fatalf("PlanForce re-cloned existing NvChad: %v", c)
+		}
+	}
+	// pacman reinstall must have fired.
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall call; calls=%v", r.runCalls)
+	}
+	// chadrc.lua was rewritten with the requested theme.
+	chadrc, err := os.ReadFile(filepath.Join(cfg, "lua", "chadrc.lua"))
+	if err != nil {
+		t.Fatalf("chadrc missing after force: %v", err)
+	}
+	if !strings.Contains(string(chadrc), `theme = "dracula"`) {
+		t.Fatalf("chadrc theme not applied: %s", chadrc)
+	}
+	// assets rewritten
+	for _, name := range []string{"arduino.lua", "dap.lua"} {
+		if _, err := os.Stat(filepath.Join(cfg, "lua", "plugins", name)); err != nil {
+			t.Errorf("asset %s missing after force: %v", name, err)
+		}
+	}
+}
+
+func TestPlanForceClonesIfMissing(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{"neovim": true}}
+	m := New(config.NeovimConfig{NvChadStarterRepo: "https://x/starter"}, "gruvbox", platform.NewPacman(r), platform.GitClient{Runner: r})
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec %q: %v", a.Description, err)
+		}
+	}
+	sawClone := false
+	for _, c := range r.runCalls {
+		if c[0] == "git" && len(c) >= 2 && c[1] == "clone" {
+			sawClone = true
+		}
+	}
+	if !sawClone {
+		t.Fatalf("expected git clone when NvChad absent; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/packages/packages.go

@@ -0,0 +1,86 @@
+// Package packages installs a declarative list of pacman packages.
+package packages
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	pkgs []string
+	pm   platform.PackageManager
+}
+
+func New(pkgs []string, pm platform.PackageManager) Module {
+	return Module{pkgs: pkgs, pm: pm}
+}
+
+type state struct{ Missing []string }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "packages", Name: "Base packages", Description: "Install base pacman package list."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []string
+	for _, p := range m.pkgs {
+		ok, err := m.pm.IsInstalled(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			missing = append(missing, p)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	missing := append([]string{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman install " + strings.Join(missing, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, missing) },
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if missing := st.(state).Missing; len(missing) > 0 {
+		return fmt.Errorf("packages not installed after apply: %v", missing)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.pkgs) == 0 {
+		return module.Plan{}, nil
+	}
+	pkgs := append([]string{}, m.pkgs...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+	}}}, nil
+}

internal/modules/packages/packages_test.go

@@ -0,0 +1,139 @@
+package packages
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool // key: pkg name
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte(args[1] + " 1.0-1\n"), nil
+		}
+		return nil, errExitOne
+	}
+	return nil, nil
+}
+
+type exitOneErr struct{}
+
+func (exitOneErr) Error() string { return "exit status 1" }
+
+var errExitOne = exitOneErr{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestDetectAbsent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"curl", "wget"}, platform.NewPacman(r))
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if len(s.Missing) != 2 {
+		t.Fatalf("want 2 missing, got %v", s.Missing)
+	}
+}
+
+func TestDetectPresent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"curl": true, "wget": true}}
+	m := New([]string{"curl", "wget"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	if len(st.(state).Missing) != 0 {
+		t.Fatalf("want 0 missing, got %v", st.(state).Missing)
+	}
+}
+
+func TestPlanAbsentEmitsInstallAction(t *testing.T) {
+	m := New([]string{"curl", "wget"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: []string{"curl", "wget"}})
+	if len(p.Actions) != 1 {
+		t.Fatalf("want 1 action, got %d", len(p.Actions))
+	}
+	if !strings.Contains(p.Actions[0].Description, "curl") {
+		t.Fatalf("desc: %s", p.Actions[0].Description)
+	}
+}
+
+func TestPlanPresentEmpty(t *testing.T) {
+	m := New([]string{"curl"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: nil})
+	if !p.IsEmpty() {
+		t.Fatal("want empty plan")
+	}
+}
+
+func TestApplyShellsOut(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"curl"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	sawInstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" {
+			sawInstall = true
+		}
+	}
+	if !sawInstall {
+		t.Fatalf("no pacman install call; calls=%v", r.runCalls)
+	}
+}
+
+func TestVerifyAfterApply(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"curl": true}}
+	m := New([]string{"curl"}, platform.NewPacman(r))
+	if err := m.Verify(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPlanForceReinstallsAllPackages(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"curl": true, "wget": true}}
+	m := New([]string{"curl", "wget"}, platform.NewPacman(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty even when packages are installed")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall (-S --noconfirm, no --needed) call; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/renode/assets/arduino-sim.tmpl

@@ -0,0 +1,54 @@
+#!/bin/bash
+set -euo pipefail
+
+usage() {
+  echo "Usage: arduino-sim <firmware.elf> [platform]"
+  echo ""
+  echo "Launch Renode with a GDB server for debugging firmware."
+  echo "Connect nvim-dap or gdb to localhost:3333"
+  echo ""
+  echo "Platforms:"
+{{range .Platforms}}  echo "  {{.Name}}    {{.Machine}}"
+{{end}}  exit 1
+}
+
+[[ $# -lt 1 ]] && usage
+
+ELF="$1"
+PLATFORM="${2:-{{(index .Platforms 0).Name}}}"
+
+[[ ! -f "$ELF" ]] && echo "Error: $ELF not found" && exit 1
+
+case "$PLATFORM" in
+{{range .Platforms}}  {{.Name}})
+    RENODE_PLATFORM="{{.ReplPath}}"
+    MACHINE="{{.Machine}}"
+    ;;
+{{end}}  *)
+    echo "Unknown platform: $PLATFORM"
+    usage
+    ;;
+esac
+
+RESC=$(mktemp /tmp/renode-XXXXXX.resc)
+cat >"$RESC" <<EOF
+using sysbus
+
+mach create "$MACHINE"
+machine LoadPlatformDescription @$RENODE_PLATFORM
+
+sysbus LoadELF @$(realpath "$ELF")
+
+machine StartGdbServer 3333
+
+showAnalyzer sysbus.uart0 Antmicro.Renode.Analyzers.LoggingUartAnalyzer
+
+start
+EOF
+
+echo "Starting Renode ($MACHINE) with GDB server on :3333"
+echo "Connect debugger:  nvim → <leader>ds  or  gdb → target remote :3333"
+echo ""
+
+renode --disable-xwt "$RESC"
+rm -f "$RESC"

internal/modules/renode/renode.go

@@ -0,0 +1,236 @@
+// Package renode installs the Renode emulator (AUR), arm-none-eabi-gdb,
+// the arduino-sim helper script, and wokwi-cli.
+package renode
+
+import (
+	"bytes"
+	"context"
+	"embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"text/template"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+//go:embed assets/arduino-sim.tmpl
+var assetsFS embed.FS
+
+// Module installs Renode and adjacent emulator tooling.
+type Module struct {
+	cfg config.RenodeConfig
+	pm  platform.PackageManager
+	aur platform.AURHelper
+}
+
+// New constructs a renode Module.
+func New(cfg config.RenodeConfig, pm platform.PackageManager, aur platform.AURHelper) Module {
+	return Module{cfg: cfg, pm: pm, aur: aur}
+}
+
+type state struct {
+	RenodeInstalled  bool
+	GdbInstalled     bool
+	SimScriptCurrent bool
+	WokwiInstalled   bool
+	RenderedSim      []byte
+	SimPath          string
+	WokwiPath        string
+}
+
+// Meta returns the module metadata.
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "renode", Name: "Renode emulator", Description: "Install Renode, ARM GDB, arduino-sim helper, and Wokwi CLI."}
+}
+
+func binPath() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".local", "bin"), nil
+}
+
+func (m Module) renderSim() ([]byte, error) {
+	tmplBytes, err := assetsFS.ReadFile("assets/arduino-sim.tmpl")
+	if err != nil {
+		return nil, err
+	}
+	tmpl, err := template.New("sim").Parse(string(tmplBytes))
+	if err != nil {
+		return nil, err
+	}
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, m.cfg); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// Detect inspects the system and returns current state.
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	bin, err := binPath()
+	if err != nil {
+		return nil, err
+	}
+	s := state{
+		SimPath:   filepath.Join(bin, "arduino-sim"),
+		WokwiPath: filepath.Join(bin, "wokwi-cli"),
+	}
+	if ok, err := m.pm.IsInstalled(ctx, "renode-bin"); err == nil && ok {
+		s.RenodeInstalled = true
+	}
+	if ok, err := m.pm.IsInstalled(ctx, "arm-none-eabi-gdb"); err == nil && ok {
+		s.GdbInstalled = true
+	}
+
+	rendered, err := m.renderSim()
+	if err != nil {
+		return nil, err
+	}
+	s.RenderedSim = rendered
+	if cur, err := os.ReadFile(s.SimPath); err == nil && bytes.Equal(cur, rendered) {
+		s.SimScriptCurrent = true
+	}
+	if _, err := os.Stat(s.WokwiPath); err == nil {
+		s.WokwiInstalled = true
+	}
+	return s, nil
+}
+
+// Plan computes the set of actions needed to converge to desired state.
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	var actions []module.Action
+
+	if !s.RenodeInstalled {
+		actions = append(actions, module.Action{
+			Description: "ensure yay installed",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.EnsureInstalled(ctx) },
+		})
+		actions = append(actions, module.Action{
+			Description: "yay install renode-bin",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.Install(ctx, []string{"renode-bin"}) },
+		})
+	}
+	if !s.GdbInstalled {
+		actions = append(actions, module.Action{
+			Description: "pacman install arm-none-eabi-gdb",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, []string{"arm-none-eabi-gdb"}) },
+		})
+	}
+	if !s.SimScriptCurrent {
+		rendered := append([]byte{}, s.RenderedSim...)
+		path := s.SimPath
+		actions = append(actions, module.Action{
+			Description: "write arduino-sim helper",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				return platform.WriteUserFile(path, rendered, 0o755)
+			},
+		})
+	}
+	if !s.WokwiInstalled {
+		url := m.cfg.WokwiURL
+		dst := s.WokwiPath
+		actions = append(actions, module.Action{
+			Description: "download wokwi-cli " + m.cfg.WokwiVersion,
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+					return err
+				}
+				return platform.Download(ctx, url, dst, 0o755)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}
+
+// Apply executes the planned actions in order.
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Verify re-Detects and errors if state hasn't converged.
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	s := st.(state)
+	if !s.RenodeInstalled {
+		return fmt.Errorf("renode-bin not installed")
+	}
+	if !s.GdbInstalled {
+		return fmt.Errorf("arm-none-eabi-gdb not installed")
+	}
+	if !s.SimScriptCurrent {
+		return fmt.Errorf("arduino-sim script drift")
+	}
+	if !s.WokwiInstalled {
+		return fmt.Errorf("wokwi-cli missing")
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	bin, err := binPath()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	rendered, err := m.renderSim()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	simPath := filepath.Join(bin, "arduino-sim")
+	wokwiPath := filepath.Join(bin, "wokwi-cli")
+
+	actions := []module.Action{
+		{
+			Description: "ensure yay installed",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.EnsureInstalled(ctx) },
+		},
+		{
+			Description: "yay -S (force) renode-bin",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.aur.Reinstall(ctx, []string{"renode-bin"}) },
+		},
+		{
+			Description: "pacman -S (force) arm-none-eabi-gdb",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, []string{"arm-none-eabi-gdb"}) },
+		},
+		{
+			Description: "rewrite arduino-sim helper (force)",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				return platform.WriteUserFile(simPath, rendered, 0o755)
+			},
+		},
+		{
+			Description: "redownload wokwi-cli " + m.cfg.WokwiVersion + " (force)",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				if err := os.MkdirAll(filepath.Dir(wokwiPath), 0o755); err != nil {
+					return err
+				}
+				return platform.Download(ctx, m.cfg.WokwiURL, wokwiPath, 0o755)
+			},
+		},
+	}
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/renode/renode_test.go

@@ -0,0 +1,193 @@
+package renode
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls, outCalls [][]string
+	installed          map[string]bool
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte("ok"), nil
+		}
+		return nil, errExit1
+	}
+	return nil, nil
+}
+
+type exitOne struct{}
+
+func (exitOne) Error() string { return "exit 1" }
+
+var errExit1 = exitOne{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func sampleCfg(url string) config.RenodeConfig {
+	return config.RenodeConfig{
+		WokwiVersion: "0.28.1",
+		WokwiURL:     url,
+		Platforms: []config.RenodePlatform{
+			{Name: "stm32f4", ReplPath: "platforms/boards/stm32f4_discovery.repl", Machine: "STM32F4_Discovery"},
+			{Name: "rp2040", ReplPath: "platforms/cpus/rp2040.repl", Machine: "RP2040"},
+		},
+	}
+}
+
+func TestDetectNothingInstalled(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(sampleCfg("http://x/wokwi"), platform.NewPacman(r), platform.NewYay(r))
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if s.RenodeInstalled || s.GdbInstalled || s.SimScriptCurrent || s.WokwiInstalled {
+		t.Fatalf("want all absent, got %+v", s)
+	}
+}
+
+func TestDetectAllInstalled(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.MkdirAll(filepath.Join(home, ".local", "bin"), 0o755)
+	os.WriteFile(filepath.Join(home, ".local", "bin", "wokwi-cli"), []byte("x"), 0o755)
+	r := &fakeRunner{installed: map[string]bool{"renode-bin": true, "arm-none-eabi-gdb": true}}
+	m := New(sampleCfg("http://x/wokwi"), platform.NewPacman(r), platform.NewYay(r))
+	// Apply once to seed the sim script, then re-detect.
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	_ = m.Apply(context.Background(), p, nopReporter{})
+	st2, _ := m.Detect(context.Background())
+	p2, _ := m.Plan(context.Background(), st2)
+	if !p2.IsEmpty() {
+		t.Fatalf("second plan not empty: %+v", p2.Actions)
+	}
+}
+
+func TestApplyRendersSimScriptAndDownloadsWokwi(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Write([]byte("wokwi-binary"))
+	}))
+	defer srv.Close()
+
+	r := &fakeRunner{installed: map[string]bool{"yay": true}}
+	m := New(sampleCfg(srv.URL), platform.NewPacman(r), platform.NewYay(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+
+	// arduino-sim rendered with both platforms
+	sim, err := os.ReadFile(filepath.Join(home, ".local", "bin", "arduino-sim"))
+	if err != nil {
+		t.Fatalf("arduino-sim not written: %v", err)
+	}
+	if !strings.Contains(string(sim), "stm32f4)") {
+		t.Errorf("stm32f4 branch missing: %s", sim)
+	}
+	if !strings.Contains(string(sim), "rp2040)") {
+		t.Errorf("rp2040 branch missing: %s", sim)
+	}
+	info, _ := os.Stat(filepath.Join(home, ".local", "bin", "arduino-sim"))
+	if info.Mode().Perm() != 0o755 {
+		t.Errorf("arduino-sim mode %v", info.Mode().Perm())
+	}
+
+	// wokwi-cli downloaded
+	wokwi, err := os.ReadFile(filepath.Join(home, ".local", "bin", "wokwi-cli"))
+	if err != nil {
+		t.Fatalf("wokwi-cli missing: %v", err)
+	}
+	if string(wokwi) != "wokwi-binary" {
+		t.Errorf("wokwi-cli content %q", wokwi)
+	}
+
+	// yay install renode-bin called
+	sawYay := false
+	for _, c := range r.runCalls {
+		if c[0] == "yay" && len(c) >= 2 && c[1] == "-S" {
+			sawYay = true
+		}
+	}
+	if !sawYay {
+		t.Fatalf("yay install missing; calls=%v", r.runCalls)
+	}
+}
+
+func TestPlanForceReinstallsEverything(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Write([]byte("wokwi-forced"))
+	}))
+	defer srv.Close()
+
+	// Even with everything already "installed", force plan should be non-empty.
+	os.MkdirAll(filepath.Join(home, ".local", "bin"), 0o755)
+	os.WriteFile(filepath.Join(home, ".local", "bin", "wokwi-cli"), []byte("stale"), 0o755)
+	r := &fakeRunner{installed: map[string]bool{"yay": true, "renode-bin": true, "arm-none-eabi-gdb": true}}
+	m := New(sampleCfg(srv.URL), platform.NewPacman(r), platform.NewYay(r))
+
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec %q: %v", a.Description, err)
+		}
+	}
+	var sawYayReinstall, sawPacmanReinstall bool
+	for _, c := range r.runCalls {
+		if len(c) >= 3 && c[0] == "yay" && c[1] == "-S" && c[2] == "--noconfirm" {
+			sawYayReinstall = true
+		}
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawPacmanReinstall = true
+		}
+	}
+	if !sawYayReinstall {
+		t.Errorf("no yay reinstall call; calls=%v", r.runCalls)
+	}
+	if !sawPacmanReinstall {
+		t.Errorf("no pacman reinstall call; calls=%v", r.runCalls)
+	}
+	// wokwi-cli should have been overwritten with the fresh payload
+	wokwi, _ := os.ReadFile(filepath.Join(home, ".local", "bin", "wokwi-cli"))
+	if string(wokwi) != "wokwi-forced" {
+		t.Errorf("wokwi-cli not overwritten: %q", wokwi)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/shellconfig/shellconfig.go

@@ -0,0 +1,109 @@
+// Package shellconfig writes marker-delimited blocks into rc files.
+package shellconfig
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct{ cfg config.ShellConfigSection }
+
+func New(cfg config.ShellConfigSection) Module { return Module{cfg: cfg} }
+
+type state struct{ Missing []config.ShellConfigBlock }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "shellconfig", Name: "Shell config blocks", Description: "Write archduino blocks into rc files."}
+}
+
+func resolveFile(name string) (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, name), nil
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []config.ShellConfigBlock
+	for _, b := range m.cfg.Blocks {
+		p, err := resolveFile(b.File)
+		if err != nil {
+			return nil, err
+		}
+		has, err := platform.HasBlock(p, b.Name)
+		if err != nil {
+			return nil, err
+		}
+		if !has {
+			missing = append(missing, b)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	var actions []module.Action
+	for _, b := range s.Missing {
+		b := b
+		actions = append(actions, module.Action{
+			Description: fmt.Sprintf("write block %s into %s", b.Name, b.File),
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				p, err := resolveFile(b.File)
+				if err != nil {
+					return err
+				}
+				return platform.EnsureBlock(p, b.Name, b.Content)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if miss := st.(state).Missing; len(miss) > 0 {
+		return fmt.Errorf("shell blocks still missing: %d", len(miss))
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	var actions []module.Action
+	for _, b := range m.cfg.Blocks {
+		b := b
+		actions = append(actions, module.Action{
+			Description: fmt.Sprintf("rewrite block %s into %s (force)", b.Name, b.File),
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				p, err := resolveFile(b.File)
+				if err != nil {
+					return err
+				}
+				return platform.EnsureBlock(p, b.Name, b.Content)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/shellconfig/shellconfig_test.go

@@ -0,0 +1,96 @@
+package shellconfig
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+type nop struct{}
+
+func (nop) Progress(string, int, int, string) {}
+func (nop) Log(string, string)                {}
+
+func TestShellConfigWritesBlocks(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	m := New(config.ShellConfigSection{
+		Blocks: []config.ShellConfigBlock{
+			{Name: "path", File: ".zshrc", Content: `export PATH="$HOME/.local/bin:$PATH"`},
+		},
+	})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+	data, _ := os.ReadFile(filepath.Join(home, ".zshrc"))
+	if !strings.Contains(string(data), ">>> path >>>") {
+		t.Fatalf("block not present: %q", data)
+	}
+	if !strings.Contains(string(data), `export PATH="$HOME/.local/bin:$PATH"`) {
+		t.Fatalf("content missing: %q", data)
+	}
+}
+
+func TestShellConfigIdempotent(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	cfg := config.ShellConfigSection{Blocks: []config.ShellConfigBlock{
+		{Name: "x", File: ".zshrc", Content: "echo x"},
+	}}
+	m := New(cfg)
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	_ = m.Apply(context.Background(), p, nop{})
+	st2, _ := m.Detect(context.Background())
+	p2, _ := m.Plan(context.Background(), st2)
+	if !p2.IsEmpty() {
+		t.Fatalf("second plan not empty: %+v", p2.Actions)
+	}
+}
+
+func TestPlanForceRewritesBlocks(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	cfg := config.ShellConfigSection{Blocks: []config.ShellConfigBlock{
+		{Name: "path", File: ".zshrc", Content: `export PATH="$HOME/.local/bin:$PATH"`},
+	}}
+	m := New(cfg)
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+	st2, _ := m.Detect(context.Background())
+	p2, _ := m.Plan(context.Background(), st2)
+	if !p2.IsEmpty() {
+		t.Fatalf("precondition: regular plan should be empty")
+	}
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	data, _ := os.ReadFile(filepath.Join(home, ".zshrc"))
+	if !strings.Contains(string(data), `export PATH="$HOME/.local/bin:$PATH"`) {
+		t.Fatalf("content missing after force: %q", data)
+	}
+	if !strings.Contains(string(data), ">>> path >>>") {
+		t.Fatalf("block marker missing: %q", data)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/starship/starship.go

@@ -0,0 +1,86 @@
+// Package starship installs a declarative list of pacman packages.
+package starship
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	pkgs []string
+	pm   platform.PackageManager
+}
+
+func New(pkgs []string, pm platform.PackageManager) Module {
+	return Module{pkgs: pkgs, pm: pm}
+}
+
+type state struct{ Missing []string }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "starship", Name: "Starship prompt", Description: "Install starship prompt."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []string
+	for _, p := range m.pkgs {
+		ok, err := m.pm.IsInstalled(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			missing = append(missing, p)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	missing := append([]string{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman install " + strings.Join(missing, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, missing) },
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if missing := st.(state).Missing; len(missing) > 0 {
+		return fmt.Errorf("packages not installed after apply: %v", missing)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.pkgs) == 0 {
+		return module.Plan{}, nil
+	}
+	pkgs := append([]string{}, m.pkgs...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+	}}}, nil
+}

internal/modules/starship/starship_test.go

@@ -0,0 +1,139 @@
+package starship
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool // key: pkg name
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte(args[1] + " 1.0-1\n"), nil
+		}
+		return nil, errExitOne
+	}
+	return nil, nil
+}
+
+type exitOneErr struct{}
+
+func (exitOneErr) Error() string { return "exit status 1" }
+
+var errExitOne = exitOneErr{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestDetectAbsent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"starship"}, platform.NewPacman(r))
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if len(s.Missing) != 1 {
+		t.Fatalf("want 1 missing, got %v", s.Missing)
+	}
+}
+
+func TestDetectPresent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"starship": true}}
+	m := New([]string{"starship"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	if len(st.(state).Missing) != 0 {
+		t.Fatalf("want 0 missing, got %v", st.(state).Missing)
+	}
+}
+
+func TestPlanAbsentEmitsInstallAction(t *testing.T) {
+	m := New([]string{"starship"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: []string{"starship"}})
+	if len(p.Actions) != 1 {
+		t.Fatalf("want 1 action, got %d", len(p.Actions))
+	}
+	if !strings.Contains(p.Actions[0].Description, "starship") {
+		t.Fatalf("desc: %s", p.Actions[0].Description)
+	}
+}
+
+func TestPlanPresentEmpty(t *testing.T) {
+	m := New([]string{"starship"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: nil})
+	if !p.IsEmpty() {
+		t.Fatal("want empty plan")
+	}
+}
+
+func TestApplyShellsOut(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"starship"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	sawInstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" {
+			sawInstall = true
+		}
+	}
+	if !sawInstall {
+		t.Fatalf("no pacman install call; calls=%v", r.runCalls)
+	}
+}
+
+func TestVerifyAfterApply(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"starship": true}}
+	m := New([]string{"starship"}, platform.NewPacman(r))
+	if err := m.Verify(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPlanForceReinstallsAllPackages(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"starship": true}}
+	m := New([]string{"starship"}, platform.NewPacman(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty even when packages are installed")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall call; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/themes/themes.go

@@ -0,0 +1,159 @@
+// Package themes installs archduino theme files into ~/.config/archduino/themes.
+package themes
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+type Module struct{ cfg config.ThemesConfig }
+
+func New(cfg config.ThemesConfig) Module { return Module{cfg: cfg} }
+
+type filePair struct{ src, dst string }
+type state struct{ Missing []filePair }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "themes", Name: "Colorscheme themes", Description: "Install archduino themes."}
+}
+
+func destRoot() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".config", "archduino", "themes"), nil
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	dst, err := destRoot()
+	if err != nil {
+		return nil, err
+	}
+	var missing []filePair
+	err = filepath.WalkDir(m.cfg.Source, func(p string, d fs.DirEntry, werr error) error {
+		if werr != nil {
+			return werr
+		}
+		if d.IsDir() {
+			return nil
+		}
+		rel, _ := filepath.Rel(m.cfg.Source, p)
+		target := filepath.Join(dst, rel)
+		a, errA := os.ReadFile(p)
+		if errA != nil {
+			return errA
+		}
+		b, errB := os.ReadFile(target)
+		if errB != nil || !bytes.Equal(a, b) {
+			missing = append(missing, filePair{src: p, dst: target})
+		}
+		return nil
+	})
+	if err != nil {
+		if os.IsNotExist(err) {
+			return state{}, nil
+		}
+		return nil, err
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	pairs := append([]filePair{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{{
+		Description: fmt.Sprintf("copy %d theme files", len(pairs)),
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			for _, fp := range pairs {
+				if err := os.MkdirAll(filepath.Dir(fp.dst), 0o755); err != nil {
+					return err
+				}
+				data, err := os.ReadFile(fp.src)
+				if err != nil {
+					return err
+				}
+				if err := os.WriteFile(fp.dst, data, 0o644); err != nil {
+					return err
+				}
+			}
+			return nil
+		},
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if miss := st.(state).Missing; len(miss) > 0 {
+		return fmt.Errorf("themes still missing: %d files", len(miss))
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	dst, err := destRoot()
+	if err != nil {
+		return module.Plan{}, err
+	}
+	var pairs []filePair
+	err = filepath.WalkDir(m.cfg.Source, func(p string, d fs.DirEntry, werr error) error {
+		if werr != nil {
+			return werr
+		}
+		if d.IsDir() {
+			return nil
+		}
+		rel, _ := filepath.Rel(m.cfg.Source, p)
+		pairs = append(pairs, filePair{src: p, dst: filepath.Join(dst, rel)})
+		return nil
+	})
+	if err != nil && !os.IsNotExist(err) {
+		return module.Plan{}, err
+	}
+	if len(pairs) == 0 {
+		return module.Plan{}, nil
+	}
+	return module.Plan{Actions: []module.Action{{
+		Description: fmt.Sprintf("rewrite %d theme files (force)", len(pairs)),
+		Kind:        module.ActionFileWrite,
+		Exec: func(ctx context.Context) error {
+			for _, fp := range pairs {
+				if err := os.MkdirAll(filepath.Dir(fp.dst), 0o755); err != nil {
+					return err
+				}
+				data, err := os.ReadFile(fp.src)
+				if err != nil {
+					return err
+				}
+				if err := os.WriteFile(fp.dst, data, 0o644); err != nil {
+					return err
+				}
+			}
+			return nil
+		},
+	}}}, nil
+}

internal/modules/themes/themes_test.go

@@ -0,0 +1,111 @@
+package themes
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+type nop struct{}
+
+func (nop) Progress(string, int, int, string) {}
+func (nop) Log(string, string)                {}
+
+func TestThemesCopiesFiles(t *testing.T) {
+	src := t.TempDir()
+	if err := os.WriteFile(filepath.Join(src, "one.toml"), []byte("A"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	os.MkdirAll(filepath.Join(src, "sub"), 0o755)
+	os.WriteFile(filepath.Join(src, "sub", "two.toml"), []byte("B"), 0o644)
+
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	m := New(config.ThemesConfig{Source: src})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+
+	got, _ := os.ReadFile(filepath.Join(home, ".config", "archduino", "themes", "one.toml"))
+	if string(got) != "A" {
+		t.Fatalf("one.toml: %q", got)
+	}
+	got, _ = os.ReadFile(filepath.Join(home, ".config", "archduino", "themes", "sub", "two.toml"))
+	if string(got) != "B" {
+		t.Fatalf("two.toml: %q", got)
+	}
+}
+
+func TestThemesIdempotent(t *testing.T) {
+	src := t.TempDir()
+	os.WriteFile(filepath.Join(src, "x.toml"), []byte("X"), 0o644)
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	m := New(config.ThemesConfig{Source: src})
+	_ = applyOnce(t, m)
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if !p.IsEmpty() {
+		t.Fatalf("second plan not empty: %+v", p.Actions)
+	}
+}
+
+func applyOnce(t *testing.T, m Module) error {
+	t.Helper()
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	return m.Apply(context.Background(), p, nop{})
+}
+
+func TestPlanForceRewritesAllThemes(t *testing.T) {
+	src := t.TempDir()
+	os.WriteFile(filepath.Join(src, "one.toml"), []byte("FRESH-A"), 0o644)
+	os.MkdirAll(filepath.Join(src, "sub"), 0o755)
+	os.WriteFile(filepath.Join(src, "sub", "two.toml"), []byte("FRESH-B"), 0o644)
+
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	m := New(config.ThemesConfig{Source: src})
+	dst := filepath.Join(home, ".config", "archduino", "themes")
+	os.MkdirAll(filepath.Join(dst, "sub"), 0o755)
+	os.WriteFile(filepath.Join(dst, "one.toml"), []byte("FRESH-A"), 0o644)
+	os.WriteFile(filepath.Join(dst, "sub", "two.toml"), []byte("FRESH-B"), 0o644)
+
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if !p.IsEmpty() {
+		t.Fatalf("precondition: plan should be empty, got %+v", p.Actions)
+	}
+
+	os.WriteFile(filepath.Join(dst, "one.toml"), []byte("STALE"), 0o644)
+	os.WriteFile(filepath.Join(dst, "sub", "two.toml"), []byte("STALE"), 0o644)
+
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	got, _ := os.ReadFile(filepath.Join(dst, "one.toml"))
+	if string(got) != "FRESH-A" {
+		t.Fatalf("one.toml not rewritten: %q", got)
+	}
+	got, _ = os.ReadFile(filepath.Join(dst, "sub", "two.toml"))
+	if string(got) != "FRESH-B" {
+		t.Fatalf("two.toml not rewritten: %q", got)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/yazi/yazi.go

@@ -0,0 +1,86 @@
+// Package yazi installs a declarative list of pacman packages.
+package yazi
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	pkgs []string
+	pm   platform.PackageManager
+}
+
+func New(pkgs []string, pm platform.PackageManager) Module {
+	return Module{pkgs: pkgs, pm: pm}
+}
+
+type state struct{ Missing []string }
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "yazi", Name: "Yazi file manager", Description: "Install yazi."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var missing []string
+	for _, p := range m.pkgs {
+		ok, err := m.pm.IsInstalled(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			missing = append(missing, p)
+		}
+	}
+	return state{Missing: missing}, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	if len(s.Missing) == 0 {
+		return module.Plan{}, nil
+	}
+	missing := append([]string{}, s.Missing...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman install " + strings.Join(missing, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, missing) },
+	}}}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	if missing := st.(state).Missing; len(missing) > 0 {
+		return fmt.Errorf("packages not installed after apply: %v", missing)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	if len(m.pkgs) == 0 {
+		return module.Plan{}, nil
+	}
+	pkgs := append([]string{}, m.pkgs...)
+	return module.Plan{Actions: []module.Action{{
+		Description: "pacman -S (force) " + strings.Join(pkgs, ", "),
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, pkgs) },
+	}}}, nil
+}

internal/modules/yazi/yazi_test.go

@@ -0,0 +1,139 @@
+package yazi
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool // key: pkg name
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte(args[1] + " 1.0-1\n"), nil
+		}
+		return nil, errExitOne
+	}
+	return nil, nil
+}
+
+type exitOneErr struct{}
+
+func (exitOneErr) Error() string { return "exit status 1" }
+
+var errExitOne = exitOneErr{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestDetectAbsent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"yazi"}, platform.NewPacman(r))
+	st, err := m.Detect(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := st.(state)
+	if len(s.Missing) != 1 {
+		t.Fatalf("want 1 missing, got %v", s.Missing)
+	}
+}
+
+func TestDetectPresent(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yazi": true}}
+	m := New([]string{"yazi"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	if len(st.(state).Missing) != 0 {
+		t.Fatalf("want 0 missing, got %v", st.(state).Missing)
+	}
+}
+
+func TestPlanAbsentEmitsInstallAction(t *testing.T) {
+	m := New([]string{"yazi"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: []string{"yazi"}})
+	if len(p.Actions) != 1 {
+		t.Fatalf("want 1 action, got %d", len(p.Actions))
+	}
+	if !strings.Contains(p.Actions[0].Description, "yazi") {
+		t.Fatalf("desc: %s", p.Actions[0].Description)
+	}
+}
+
+func TestPlanPresentEmpty(t *testing.T) {
+	m := New([]string{"yazi"}, nil)
+	p, _ := m.Plan(context.Background(), state{Missing: nil})
+	if !p.IsEmpty() {
+		t.Fatal("want empty plan")
+	}
+}
+
+func TestApplyShellsOut(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New([]string{"yazi"}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	sawInstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" {
+			sawInstall = true
+		}
+	}
+	if !sawInstall {
+		t.Fatalf("no pacman install call; calls=%v", r.runCalls)
+	}
+}
+
+func TestVerifyAfterApply(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yazi": true}}
+	m := New([]string{"yazi"}, platform.NewPacman(r))
+	if err := m.Verify(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPlanForceReinstallsAllPackages(t *testing.T) {
+	r := &fakeRunner{installed: map[string]bool{"yazi": true}}
+	m := New([]string{"yazi"}, platform.NewPacman(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty even when packages are installed")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall call; calls=%v", r.runCalls)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/zellij/zellij.go

@@ -0,0 +1,135 @@
+// Package zellij installs zellij and optionally writes a remote config.
+package zellij
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	cfg config.ZellijConfig
+	pm  platform.PackageManager
+}
+
+func New(cfg config.ZellijConfig, pm platform.PackageManager) Module {
+	return Module{cfg: cfg, pm: pm}
+}
+
+type state struct {
+	Installed  bool
+	ConfigOK   bool
+	ConfigPath string
+}
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "zellij", Name: "Zellij terminal multiplexer", Description: "Install zellij and config."}
+}
+
+func configPath() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".config", "zellij", "config.kdl"), nil
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var s state
+	ok, err := m.pm.IsInstalled(ctx, "zellij")
+	if err != nil {
+		return nil, err
+	}
+	s.Installed = ok
+	p, err := configPath()
+	if err != nil {
+		return nil, err
+	}
+	s.ConfigPath = p
+	if m.cfg.ConfigURL == "" {
+		s.ConfigOK = true
+	} else if _, err := os.Stat(p); err == nil {
+		s.ConfigOK = true
+	}
+	return s, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	var actions []module.Action
+	if !s.Installed {
+		actions = append(actions, module.Action{
+			Description: "pacman install zellij",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, []string{"zellij"}) },
+		})
+	}
+	if !s.ConfigOK {
+		actions = append(actions, module.Action{
+			Description: "download zellij config",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				if err := os.MkdirAll(filepath.Dir(s.ConfigPath), 0o755); err != nil {
+					return err
+				}
+				return platform.Download(ctx, m.cfg.ConfigURL, s.ConfigPath, 0o644)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	s := st.(state)
+	if !s.Installed {
+		return fmt.Errorf("zellij not installed")
+	}
+	if !s.ConfigOK {
+		return fmt.Errorf("zellij config missing")
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	actions := []module.Action{{
+		Description: "pacman -S (force) zellij",
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, []string{"zellij"}) },
+	}}
+	if m.cfg.ConfigURL != "" {
+		p, err := configPath()
+		if err != nil {
+			return module.Plan{}, err
+		}
+		actions = append(actions, module.Action{
+			Description: "redownload zellij config (force)",
+			Kind:        module.ActionFileWrite,
+			Exec: func(ctx context.Context) error {
+				if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
+					return err
+				}
+				return platform.Download(ctx, m.cfg.ConfigURL, p, 0o644)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/zellij/zellij_test.go

@@ -0,0 +1,125 @@
+package zellij
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte("ok"), nil
+		}
+		return nil, errOne
+	}
+	return nil, nil
+}
+
+type eo struct{}
+
+func (eo) Error() string { return "exit 1" }
+
+var errOne = eo{}
+
+type nop struct{}
+
+func (nop) Progress(string, int, int, string) {}
+func (nop) Log(string, string)                {}
+
+func TestZellijPlanAppliesInstallAndConfig(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Write([]byte("keybinds {}\n"))
+	}))
+	defer srv.Close()
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.ZellijConfig{ConfigURL: srv.URL}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if err := m.Apply(context.Background(), p, nop{}); err != nil {
+		t.Fatal(err)
+	}
+	got, err := os.ReadFile(filepath.Join(home, ".config", "zellij", "config.kdl"))
+	if err != nil {
+		t.Fatalf("config not written: %v", err)
+	}
+	if string(got) != "keybinds {}\n" {
+		t.Fatalf("unexpected content %q", got)
+	}
+}
+
+func TestZellijInstalledPresentEmptyPlan(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{"zellij": true}}
+	m := New(config.ZellijConfig{ConfigURL: ""}, platform.NewPacman(r))
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if !p.IsEmpty() {
+		t.Fatalf("want empty plan, got %+v", p)
+	}
+}
+
+func TestPlanForceReinstallsAndRewritesConfig(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.MkdirAll(filepath.Join(home, ".config", "zellij"), 0o755)
+	os.WriteFile(filepath.Join(home, ".config", "zellij", "config.kdl"), []byte("old\n"), 0o644)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Write([]byte("fresh {}\n"))
+	}))
+	defer srv.Close()
+	r := &fakeRunner{installed: map[string]bool{"zellij": true}}
+	m := New(config.ZellijConfig{ConfigURL: srv.URL}, platform.NewPacman(r))
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall := false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+	}
+	if !sawReinstall {
+		t.Fatalf("no pacman reinstall call; calls=%v", r.runCalls)
+	}
+	got, err := os.ReadFile(filepath.Join(home, ".config", "zellij", "config.kdl"))
+	if err != nil {
+		t.Fatalf("config not written: %v", err)
+	}
+	if string(got) != "fresh {}\n" {
+		t.Fatalf("config not overwritten: %q", got)
+	}
+}
+
+var _ module.Module = Module{}

internal/modules/zsh/zsh.go

@@ -0,0 +1,173 @@
+// Package zsh installs zsh, oh-my-zsh, and configured plugins.
+package zsh
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type Module struct {
+	cfg config.ZshConfig
+	pm  platform.PackageManager
+	git platform.GitClient
+}
+
+func New(cfg config.ZshConfig, pm platform.PackageManager, git platform.GitClient) Module {
+	return Module{cfg: cfg, pm: pm, git: git}
+}
+
+type state struct {
+	ZshInstalled   bool
+	OMZInstalled   bool
+	MissingPlugins []config.ZshPlugin
+}
+
+func omzHome() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".oh-my-zsh"), nil
+}
+
+func (Module) Meta() module.Meta {
+	return module.Meta{ID: "zsh", Name: "Zsh + oh-my-zsh", Description: "Install zsh, oh-my-zsh, and plugins."}
+}
+
+func (m Module) Detect(ctx context.Context) (module.State, error) {
+	var s state
+	ok, err := m.pm.IsInstalled(ctx, "zsh")
+	if err != nil {
+		return nil, err
+	}
+	s.ZshInstalled = ok
+	omz, err := omzHome()
+	if err != nil {
+		return nil, err
+	}
+	if _, err := os.Stat(omz); err == nil {
+		s.OMZInstalled = true
+	}
+	for _, p := range m.cfg.Plugins {
+		path := filepath.Join(omz, "custom", "plugins", p.Name, ".git")
+		if _, err := os.Stat(path); err != nil {
+			s.MissingPlugins = append(s.MissingPlugins, p)
+		}
+	}
+	return s, nil
+}
+
+func (m Module) Plan(ctx context.Context, cur module.State) (module.Plan, error) {
+	s, _ := cur.(state)
+	var actions []module.Action
+	if !s.ZshInstalled {
+		actions = append(actions, module.Action{
+			Description: "pacman install zsh",
+			Kind:        module.ActionPackageInstall,
+			Exec:        func(ctx context.Context) error { return m.pm.Install(ctx, []string{"zsh"}) },
+		})
+	}
+	if !s.OMZInstalled {
+		actions = append(actions, module.Action{
+			Description: "clone oh-my-zsh from " + m.cfg.OhMyZshRepo,
+			Kind:        module.ActionGitClone,
+			Exec: func(ctx context.Context) error {
+				omz, err := omzHome()
+				if err != nil {
+					return err
+				}
+				return m.git.EnsureRepo(ctx, m.cfg.OhMyZshRepo, omz)
+			},
+		})
+	}
+	for _, p := range s.MissingPlugins {
+		p := p // capture
+		actions = append(actions, module.Action{
+			Description: "clone plugin " + p.Name,
+			Kind:        module.ActionGitClone,
+			Exec: func(ctx context.Context) error {
+				omz, err := omzHome()
+				if err != nil {
+					return err
+				}
+				return m.git.EnsureRepo(ctx, p.Repo, filepath.Join(omz, "custom", "plugins", p.Name))
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}
+
+func (m Module) Apply(ctx context.Context, p module.Plan, r module.Reporter) error {
+	for i, a := range p.Actions {
+		r.Progress(m.Meta().ID, i+1, len(p.Actions), a.Description)
+		if err := a.Exec(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m Module) Verify(ctx context.Context) error {
+	st, err := m.Detect(ctx)
+	if err != nil {
+		return err
+	}
+	s := st.(state)
+	if !s.ZshInstalled {
+		return fmt.Errorf("zsh not installed")
+	}
+	if !s.OMZInstalled {
+		return fmt.Errorf("oh-my-zsh not installed")
+	}
+	if len(s.MissingPlugins) > 0 {
+		return fmt.Errorf("plugins missing: %v", s.MissingPlugins)
+	}
+	return nil
+}
+
+func (m Module) PlanForce(ctx context.Context) (module.Plan, error) {
+	actions := []module.Action{{
+		Description: "pacman -S (force) zsh",
+		Kind:        module.ActionPackageInstall,
+		Exec:        func(ctx context.Context) error { return m.pm.Reinstall(ctx, []string{"zsh"}) },
+	}}
+	actions = append(actions, module.Action{
+		Description: "reclone oh-my-zsh from " + m.cfg.OhMyZshRepo + " (force)",
+		Kind:        module.ActionGitClone,
+		Exec: func(ctx context.Context) error {
+			omz, err := omzHome()
+			if err != nil {
+				return err
+			}
+			if err := os.RemoveAll(omz); err != nil {
+				return err
+			}
+			return m.git.Clone(ctx, m.cfg.OhMyZshRepo, omz)
+		},
+	})
+	for _, p := range m.cfg.Plugins {
+		p := p
+		actions = append(actions, module.Action{
+			Description: "reclone plugin " + p.Name + " (force)",
+			Kind:        module.ActionGitClone,
+			Exec: func(ctx context.Context) error {
+				omz, err := omzHome()
+				if err != nil {
+					return err
+				}
+				dest := filepath.Join(omz, "custom", "plugins", p.Name)
+				if err := os.RemoveAll(dest); err != nil {
+					return err
+				}
+				return m.git.Clone(ctx, p.Repo, dest)
+			},
+		})
+	}
+	return module.Plan{Actions: actions}, nil
+}

internal/modules/zsh/zsh_test.go

@@ -0,0 +1,159 @@
+package zsh
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+type fakeRunner struct {
+	runCalls  [][]string
+	outCalls  [][]string
+	installed map[string]bool
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" {
+		if f.installed[args[1]] {
+			return []byte("ok"), nil
+		}
+		return nil, errOne
+	}
+	return nil, nil
+}
+
+type eo struct{}
+
+func (eo) Error() string { return "exit 1" }
+
+var errOne = eo{}
+
+type nopReporter struct{}
+
+func (nopReporter) Progress(string, int, int, string) {}
+func (nopReporter) Log(string, string)                {}
+
+func TestZshDetectAbsent(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.ZshConfig{
+		OhMyZshRepo: "https://x/omz.git",
+		Plugins:     []config.ZshPlugin{{Name: "zsh-autosuggestions", Repo: "https://x/a.git"}},
+	}, platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	s := st.(state)
+	if s.ZshInstalled {
+		t.Error("want zsh absent")
+	}
+	if s.OMZInstalled {
+		t.Error("want omz absent")
+	}
+	if len(s.MissingPlugins) != 1 {
+		t.Errorf("want 1 plugin missing, got %v", s.MissingPlugins)
+	}
+}
+
+func TestZshDetectAllPresent(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.MkdirAll(filepath.Join(home, ".oh-my-zsh"), 0o755)
+	os.MkdirAll(filepath.Join(home, ".oh-my-zsh", "custom", "plugins", "zsh-autosuggestions", ".git"), 0o755)
+	r := &fakeRunner{installed: map[string]bool{"zsh": true}}
+	m := New(config.ZshConfig{
+		OhMyZshRepo: "https://x/omz.git",
+		Plugins:     []config.ZshPlugin{{Name: "zsh-autosuggestions", Repo: "https://x/a.git"}},
+	}, platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	s := st.(state)
+	if !s.ZshInstalled || !s.OMZInstalled || len(s.MissingPlugins) != 0 {
+		t.Fatalf("want all present, got %+v", s)
+	}
+}
+
+func TestZshPlanApplyInstallsEverything(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	r := &fakeRunner{installed: map[string]bool{}}
+	m := New(config.ZshConfig{
+		OhMyZshRepo: "https://x/omz.git",
+		Plugins:     []config.ZshPlugin{{Name: "zsh-autosuggestions", Repo: "https://x/a.git"}},
+	}, platform.NewPacman(r), platform.GitClient{Runner: r})
+	st, _ := m.Detect(context.Background())
+	p, _ := m.Plan(context.Background(), st)
+	if len(p.Actions) == 0 {
+		t.Fatal("want non-empty plan")
+	}
+	if err := m.Apply(context.Background(), p, nopReporter{}); err != nil {
+		t.Fatal(err)
+	}
+	sawPacman, sawOMZ, sawPlugin := false, false, false
+	for _, c := range r.runCalls {
+		if len(c) >= 3 && c[0] == "sudo" && c[1] == "pacman" {
+			sawPacman = true
+		}
+		if len(c) >= 4 && c[0] == "git" && c[3] == "https://x/omz.git" {
+			sawOMZ = true
+		}
+		if len(c) >= 4 && c[0] == "git" && c[3] == "https://x/a.git" {
+			sawPlugin = true
+		}
+	}
+	if !sawPacman || !sawOMZ || !sawPlugin {
+		t.Fatalf("missing step; calls=%v", r.runCalls)
+	}
+}
+
+func TestPlanForceReinstallsEverything(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	os.MkdirAll(filepath.Join(home, ".oh-my-zsh", ".git"), 0o755)
+	os.MkdirAll(filepath.Join(home, ".oh-my-zsh", "custom", "plugins", "zsh-autosuggestions", ".git"), 0o755)
+	r := &fakeRunner{installed: map[string]bool{"zsh": true}}
+	m := New(config.ZshConfig{
+		OhMyZshRepo: "https://x/omz.git",
+		Plugins:     []config.ZshPlugin{{Name: "zsh-autosuggestions", Repo: "https://x/a.git"}},
+	}, platform.NewPacman(r), platform.GitClient{Runner: r})
+	plan, err := m.PlanForce(context.Background())
+	if err != nil {
+		t.Fatalf("PlanForce: %v", err)
+	}
+	if plan.IsEmpty() {
+		t.Fatal("force plan must not be empty")
+	}
+	for _, a := range plan.Actions {
+		if err := a.Exec(context.Background()); err != nil {
+			t.Fatalf("Exec: %v", err)
+		}
+	}
+	sawReinstall, sawOMZ, sawPlugin := false, false, false
+	for _, c := range r.runCalls {
+		if len(c) >= 4 && c[0] == "sudo" && c[1] == "pacman" && c[2] == "-S" && c[3] == "--noconfirm" {
+			sawReinstall = true
+		}
+		if len(c) >= 4 && c[0] == "git" && c[3] == "https://x/omz.git" {
+			sawOMZ = true
+		}
+		if len(c) >= 4 && c[0] == "git" && c[3] == "https://x/a.git" {
+			sawPlugin = true
+		}
+	}
+	if !sawReinstall || !sawOMZ || !sawPlugin {
+		t.Fatalf("missing force action; calls=%v", r.runCalls)
+	}
+	if _, err := os.Stat(filepath.Join(home, ".oh-my-zsh")); !os.IsNotExist(err) {
+		t.Fatalf("oh-my-zsh dir should have been removed; stat err=%v", err)
+	}
+}
+
+var _ module.Module = Module{}

internal/platform/aur.go

@@ -0,0 +1,69 @@
+package platform
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// AURHelper abstracts an AUR front-end (currently only yay).
+type AURHelper interface {
+	EnsureInstalled(ctx context.Context) error
+	Install(ctx context.Context, pkgs []string) error
+	Reinstall(ctx context.Context, pkgs []string) error
+}
+
+type Yay struct {
+	Runner Runner
+	pm     *Pacman
+}
+
+func NewYay(r Runner) *Yay { return &Yay{Runner: r, pm: NewPacman(r)} }
+
+func (y *Yay) EnsureInstalled(ctx context.Context) error {
+	ok, _ := y.pm.IsInstalled(ctx, "yay")
+	if ok {
+		return nil
+	}
+	// Bootstrap: install build deps, clone AUR yay, makepkg -si.
+	if err := y.pm.Install(ctx, []string{"base-devel", "git"}); err != nil {
+		return err
+	}
+	tmp, err := os.MkdirTemp("", "archduino-yay-")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmp)
+	clone := filepath.Join(tmp, "yay")
+	if err := y.Runner.Run(ctx, "git", "clone", "https://aur.archlinux.org/yay.git", clone); err != nil {
+		return err
+	}
+	// `makepkg -si --noconfirm` needs to cd into the cloned dir. os/exec does
+	// not have a per-command cwd without exec.Cmd; our Runner interface does
+	// not expose that, so we invoke via sh -c with a pushd-style prefix.
+	return y.Runner.Run(ctx, "sh", "-c", "cd "+shellQuote(clone)+" && makepkg -si --noconfirm")
+}
+
+func (y *Yay) Install(ctx context.Context, pkgs []string) error {
+	if len(pkgs) == 0 {
+		return nil
+	}
+	args := append([]string{"-S", "--needed", "--noconfirm"}, pkgs...)
+	return y.Runner.Run(ctx, "yay", args...)
+}
+
+// Reinstall runs `yay -S --noconfirm <pkgs...>` WITHOUT `--needed`, forcing
+// yay/pacman to re-fetch and reinstall the packages even if already present.
+// Used by the `--force` flag to bypass idempotency.
+func (y *Yay) Reinstall(ctx context.Context, pkgs []string) error {
+	if len(pkgs) == 0 {
+		return nil
+	}
+	args := append([]string{"-S", "--noconfirm"}, pkgs...)
+	return y.Runner.Run(ctx, "yay", args...)
+}
+
+func shellQuote(s string) string {
+	return "'" + strings.ReplaceAll(s, "'", `'\''`) + "'"
+}

internal/platform/aur_test.go

@@ -0,0 +1,115 @@
+package platform
+
+import (
+	"context"
+	"strings"
+	"testing"
+)
+
+type aurFakeRunner struct {
+	runCalls [][]string
+	outCalls [][]string
+	// yayInstalled toggles what `pacman -Q yay` returns.
+	yayInstalled bool
+}
+
+func (f *aurFakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *aurFakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outCalls = append(f.outCalls, append([]string{name}, args...))
+	if name == "pacman" && len(args) == 2 && args[0] == "-Q" && args[1] == "yay" {
+		if f.yayInstalled {
+			return []byte("yay 12.0-1\n"), nil
+		}
+		return nil, &fakeExitErr{}
+	}
+	return nil, nil
+}
+
+type fakeExitErr struct{}
+
+func (fakeExitErr) Error() string { return "exit 1" }
+
+func TestAUREnsureInstalledSkipsWhenYayPresent(t *testing.T) {
+	r := &aurFakeRunner{yayInstalled: true}
+	y := NewYay(r)
+	if err := y.EnsureInstalled(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) != 0 {
+		t.Fatalf("no installs expected, got %v", r.runCalls)
+	}
+}
+
+func TestAUREnsureInstalledBootstrapsYay(t *testing.T) {
+	r := &aurFakeRunner{yayInstalled: false}
+	y := NewYay(r)
+	if err := y.EnsureInstalled(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	// Expect: pacman install base-devel+git, git clone yay, makepkg -si in that dir.
+	sawPacman := false
+	sawClone := false
+	sawMakepkg := false
+	for _, c := range r.runCalls {
+		if len(c) >= 2 && c[0] == "sudo" && c[1] == "pacman" {
+			sawPacman = true
+		}
+		if len(c) >= 2 && c[0] == "git" && c[1] == "clone" {
+			sawClone = true
+		}
+		if len(c) >= 3 && c[0] == "sh" && c[1] == "-c" && strings.Contains(c[2], "makepkg") {
+			sawMakepkg = true
+		}
+	}
+	if !sawPacman || !sawClone || !sawMakepkg {
+		t.Fatalf("missing bootstrap step; calls=%v", r.runCalls)
+	}
+}
+
+func TestYayReinstall(t *testing.T) {
+	r := &aurFakeRunner{yayInstalled: true}
+	y := NewYay(r)
+	if err := y.Reinstall(context.Background(), []string{"git", "curl"}); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) == 0 {
+		t.Fatal("expected yay reinstall call")
+	}
+	c := r.runCalls[len(r.runCalls)-1]
+	want := []string{"yay", "-S", "--noconfirm", "git", "curl"}
+	if len(c) != len(want) {
+		t.Fatalf("call = %v, want %v", c, want)
+	}
+	for i, w := range want {
+		if c[i] != w {
+			t.Fatalf("call = %v, want %v", c, want)
+		}
+	}
+	for _, a := range c {
+		if a == "--needed" {
+			t.Fatalf("Reinstall must not pass --needed; got %v", c)
+		}
+	}
+}
+
+func TestAURInstall(t *testing.T) {
+	r := &aurFakeRunner{yayInstalled: true}
+	y := NewYay(r)
+	if err := y.Install(context.Background(), []string{"ttf-jetbrains-mono-nerd"}); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) == 0 {
+		t.Fatal("expected yay install call")
+	}
+	c := r.runCalls[len(r.runCalls)-1]
+	want := []string{"yay", "-S", "--needed", "--noconfirm", "ttf-jetbrains-mono-nerd"}
+	for i, w := range want {
+		if i >= len(c) || c[i] != w {
+			t.Fatalf("call = %v, want %v", c, want)
+		}
+	}
+}

internal/platform/download.go

@@ -0,0 +1,42 @@
+package platform
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+)
+
+// Download fetches url into destPath atomically (temp file + rename) with
+// the given file mode. Any non-2xx response returns an error and leaves
+// no file behind.
+func Download(ctx context.Context, url, destPath string, mode os.FileMode) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("download %s: http %d", url, resp.StatusCode)
+	}
+	tmp := destPath + ".tmp"
+	f, err := os.OpenFile(tmp, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode)
+	if err != nil {
+		return err
+	}
+	if _, err := io.Copy(f, resp.Body); err != nil {
+		f.Close()
+		os.Remove(tmp)
+		return err
+	}
+	if err := f.Close(); err != nil {
+		os.Remove(tmp)
+		return err
+	}
+	return os.Rename(tmp, destPath)
+}

internal/platform/download_test.go

@@ -0,0 +1,45 @@
+package platform
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestDownloadHappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("payload"))
+	}))
+	defer srv.Close()
+	dir := t.TempDir()
+	dest := filepath.Join(dir, "out.bin")
+	if err := Download(context.Background(), srv.URL, dest, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(dest)
+	if string(got) != "payload" {
+		t.Fatalf("got %q want payload", got)
+	}
+	info, _ := os.Stat(dest)
+	if info.Mode().Perm() != 0o755 {
+		t.Fatalf("mode=%v want 0755", info.Mode().Perm())
+	}
+}
+
+func TestDownload404Errors(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "nope", http.StatusNotFound)
+	}))
+	defer srv.Close()
+	dir := t.TempDir()
+	dest := filepath.Join(dir, "out.bin")
+	if err := Download(context.Background(), srv.URL, dest, 0o644); err == nil {
+		t.Fatal("want error on 404")
+	}
+	if _, err := os.Stat(dest); !os.IsNotExist(err) {
+		t.Fatal("dest should not exist after failed download")
+	}
+}

internal/platform/extract.go

@@ -0,0 +1,114 @@
+package platform
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func safeJoin(dest, name string) (string, error) {
+	p := filepath.Join(dest, name)
+	cleanDest := filepath.Clean(dest) + string(os.PathSeparator)
+	if !strings.HasPrefix(filepath.Clean(p)+string(os.PathSeparator), cleanDest) {
+		return "", fmt.Errorf("unsafe path %q escapes %q", name, dest)
+	}
+	return p, nil
+}
+
+func ExtractTarGz(ctx context.Context, archivePath, destDir string) error {
+	f, err := os.Open(archivePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	gz, err := gzip.NewReader(f)
+	if err != nil {
+		return err
+	}
+	defer gz.Close()
+	tr := tar.NewReader(gz)
+	for {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		h, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		target, err := safeJoin(destDir, h.Name)
+		if err != nil {
+			return err
+		}
+		switch h.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(target, os.FileMode(h.Mode)); err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil {
+				return err
+			}
+			w, err := os.OpenFile(target, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(h.Mode))
+			if err != nil {
+				return err
+			}
+			if _, err := io.Copy(w, tr); err != nil {
+				w.Close()
+				return err
+			}
+			w.Close()
+		}
+	}
+	return nil
+}
+
+func ExtractZip(ctx context.Context, archivePath, destDir string) error {
+	zr, err := zip.OpenReader(archivePath)
+	if err != nil {
+		return err
+	}
+	defer zr.Close()
+	for _, zf := range zr.File {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		target, err := safeJoin(destDir, zf.Name)
+		if err != nil {
+			return err
+		}
+		if zf.FileInfo().IsDir() {
+			if err := os.MkdirAll(target, zf.Mode()); err != nil {
+				return err
+			}
+			continue
+		}
+		if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil {
+			return err
+		}
+		rc, err := zf.Open()
+		if err != nil {
+			return err
+		}
+		w, err := os.OpenFile(target, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, zf.Mode())
+		if err != nil {
+			rc.Close()
+			return err
+		}
+		_, err = io.Copy(w, rc)
+		rc.Close()
+		w.Close()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

internal/platform/extract_test.go

@@ -0,0 +1,80 @@
+package platform
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func makeTarGz(t *testing.T, entries map[string]string) string {
+	t.Helper()
+	p := filepath.Join(t.TempDir(), "a.tar.gz")
+	f, err := os.Create(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	gz := gzip.NewWriter(f)
+	tw := tar.NewWriter(gz)
+	for name, body := range entries {
+		tw.WriteHeader(&tar.Header{Name: name, Mode: 0o644, Size: int64(len(body))})
+		tw.Write([]byte(body))
+	}
+	tw.Close()
+	gz.Close()
+	f.Close()
+	return p
+}
+
+func makeZip(t *testing.T, entries map[string]string) string {
+	t.Helper()
+	p := filepath.Join(t.TempDir(), "a.zip")
+	f, _ := os.Create(p)
+	zw := zip.NewWriter(f)
+	for name, body := range entries {
+		w, _ := zw.Create(name)
+		w.Write([]byte(body))
+	}
+	zw.Close()
+	f.Close()
+	return p
+}
+
+func TestExtractTarGz(t *testing.T) {
+	src := makeTarGz(t, map[string]string{"hello.txt": "world", "sub/x.txt": "y"})
+	dest := t.TempDir()
+	if err := ExtractTarGz(context.Background(), src, dest); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(filepath.Join(dest, "hello.txt"))
+	if string(got) != "world" {
+		t.Fatalf("got %q", got)
+	}
+	got, _ = os.ReadFile(filepath.Join(dest, "sub", "x.txt"))
+	if string(got) != "y" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestExtractZip(t *testing.T) {
+	src := makeZip(t, map[string]string{"a.txt": "A"})
+	dest := t.TempDir()
+	if err := ExtractZip(context.Background(), src, dest); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(filepath.Join(dest, "a.txt"))
+	if string(got) != "A" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestExtractRejectsPathTraversal(t *testing.T) {
+	src := makeTarGz(t, map[string]string{"../evil.txt": "x"})
+	dest := t.TempDir()
+	if err := ExtractTarGz(context.Background(), src, dest); err == nil {
+		t.Fatal("want error on path traversal")
+	}
+}

internal/platform/git.go

@@ -0,0 +1,23 @@
+package platform
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+)
+
+// GitClient wraps `git` via a Runner.
+type GitClient struct{ Runner Runner }
+
+// Clone always runs `git clone --depth=1 url dest`.
+func (g GitClient) Clone(ctx context.Context, url, dest string) error {
+	return g.Runner.Run(ctx, "git", "clone", "--depth=1", url, dest)
+}
+
+// EnsureRepo clones url into dest if dest/.git is missing; otherwise noop.
+func (g GitClient) EnsureRepo(ctx context.Context, url, dest string) error {
+	if _, err := os.Stat(filepath.Join(dest, ".git")); err == nil {
+		return nil
+	}
+	return g.Clone(ctx, url, dest)
+}

internal/platform/git_test.go

@@ -0,0 +1,55 @@
+package platform
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+type gitFakeRunner struct {
+	calls [][]string
+	err   error
+}
+
+func (f *gitFakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.calls = append(f.calls, append([]string{name}, args...))
+	return f.err
+}
+func (f *gitFakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	return nil, nil
+}
+
+func TestGitEnsureRepoClonesWhenMissing(t *testing.T) {
+	r := &gitFakeRunner{}
+	g := GitClient{Runner: r}
+	dest := filepath.Join(t.TempDir(), "repo")
+	if err := g.EnsureRepo(context.Background(), "https://x/y.git", dest); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.calls) != 1 {
+		t.Fatalf("want 1 call, got %d: %v", len(r.calls), r.calls)
+	}
+	got := r.calls[0]
+	want := []string{"git", "clone", "--depth=1", "https://x/y.git", dest}
+	for i := range want {
+		if i >= len(got) || got[i] != want[i] {
+			t.Fatalf("call = %v, want %v", got, want)
+		}
+	}
+}
+
+func TestGitEnsureRepoSkipsWhenPresent(t *testing.T) {
+	dest := t.TempDir()
+	if err := os.MkdirAll(filepath.Join(dest, ".git"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	r := &gitFakeRunner{}
+	g := GitClient{Runner: r}
+	if err := g.EnsureRepo(context.Background(), "https://x/y.git", dest); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.calls) != 0 {
+		t.Fatalf("expected no calls, got %v", r.calls)
+	}
+}

internal/platform/pacman.go

@@ -0,0 +1,96 @@
+package platform
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+// ExecRunner runs commands via os/exec. This is the production Runner.
+type ExecRunner struct{}
+
+func (ExecRunner) Run(ctx context.Context, name string, args ...string) error {
+	cmd := exec.CommandContext(ctx, name, args...)
+	var stderr bytes.Buffer
+	cmd.Stdout = nil
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		msg := strings.TrimSpace(stderr.String())
+		if msg == "" {
+			return fmt.Errorf("%s %s: %w", name, strings.Join(args, " "), err)
+		}
+		return fmt.Errorf("%s %s: %w: %s", name, strings.Join(args, " "), err, msg)
+	}
+	return nil
+}
+
+func (ExecRunner) Output(ctx context.Context, name string, args ...string) ([]byte, error) {
+	cmd := exec.CommandContext(ctx, name, args...)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	out, err := cmd.Output()
+	if err != nil {
+		return out, fmt.Errorf("%s %s: %w: %s", name, strings.Join(args, " "), err, stderr.String())
+	}
+	return out, nil
+}
+
+// Pacman implements PackageManager via `pacman` on Arch.
+type Pacman struct {
+	Runner Runner
+}
+
+func NewPacman(r Runner) *Pacman {
+	if r == nil {
+		r = ExecRunner{}
+	}
+	return &Pacman{Runner: r}
+}
+
+func (Pacman) Name() string { return "pacman" }
+
+// IsInstalled returns true when `pacman -Q <pkg>` succeeds.
+func (p Pacman) IsInstalled(ctx context.Context, pkg string) (bool, error) {
+	if pkg == "" {
+		return false, errors.New("empty package name")
+	}
+	_, err := p.Runner.Output(ctx, "pacman", "-Q", pkg)
+	if err == nil {
+		return true, nil
+	}
+	// pacman -Q exits 1 when not installed; we treat any error as "not installed"
+	// because false-positives on transient errors here are harmless (Install
+	// is idempotent via --needed).
+	return false, nil
+}
+
+// Install runs `sudo pacman -S --needed --noconfirm <pkgs...>`.
+func (p Pacman) Install(ctx context.Context, pkgs []string) error {
+	if len(pkgs) == 0 {
+		return nil
+	}
+	args := append([]string{"pacman", "-S", "--needed", "--noconfirm"}, pkgs...)
+	return p.Runner.Run(ctx, "sudo", args...)
+}
+
+// Reinstall runs `sudo pacman -S --noconfirm <pkgs...>` WITHOUT `--needed`,
+// so pacman physically re-fetches and reinstalls the packages even if they
+// are already present. Used by the `--force` flag to bypass idempotency.
+func (p Pacman) Reinstall(ctx context.Context, pkgs []string) error {
+	if len(pkgs) == 0 {
+		return nil
+	}
+	args := append([]string{"pacman", "-S", "--noconfirm"}, pkgs...)
+	return p.Runner.Run(ctx, "sudo", args...)
+}
+
+// Update runs `sudo pacman -Syu --noconfirm` (full sync + system upgrade).
+// On Arch, a bare `pacman -Sy` followed by an install is the partial-upgrade
+// anti-pattern that can break the system when a dep's ABI changes, so we
+// always pair the sync with the upgrade.
+func (p Pacman) Update(ctx context.Context) error {
+	return p.Runner.Run(ctx, "sudo", "pacman", "-Syu", "--noconfirm")
+}

internal/platform/pacman_test.go

@@ -0,0 +1,108 @@
+package platform
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"testing"
+)
+
+type fakeRunner struct {
+	runCalls    [][]string
+	outputCalls [][]string
+	outputErr   error
+	output      []byte
+}
+
+func (f *fakeRunner) Run(_ context.Context, name string, args ...string) error {
+	f.runCalls = append(f.runCalls, append([]string{name}, args...))
+	return nil
+}
+
+func (f *fakeRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	f.outputCalls = append(f.outputCalls, append([]string{name}, args...))
+	return f.output, f.outputErr
+}
+
+func TestPacmanInstallShellsOutCorrectly(t *testing.T) {
+	r := &fakeRunner{}
+	p := NewPacman(r)
+	if err := p.Install(context.Background(), []string{"tio", "git"}); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) != 1 {
+		t.Fatalf("run calls = %d", len(r.runCalls))
+	}
+	want := []string{"sudo", "pacman", "-S", "--needed", "--noconfirm", "tio", "git"}
+	if !reflect.DeepEqual(r.runCalls[0], want) {
+		t.Fatalf("args = %v, want %v", r.runCalls[0], want)
+	}
+}
+
+func TestPacmanReinstall(t *testing.T) {
+	r := &fakeRunner{}
+	p := NewPacman(r)
+	if err := p.Reinstall(context.Background(), []string{"git", "curl"}); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) != 1 {
+		t.Fatalf("run calls = %d", len(r.runCalls))
+	}
+	got := r.runCalls[0]
+	want := []string{"sudo", "pacman", "-S", "--noconfirm", "git", "curl"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("args = %v, want %v", got, want)
+	}
+	for _, a := range got {
+		if a == "--needed" {
+			t.Fatalf("Reinstall must not pass --needed; got %v", got)
+		}
+	}
+}
+
+func TestPacmanInstallEmptyIsNoop(t *testing.T) {
+	r := &fakeRunner{}
+	p := NewPacman(r)
+	if err := p.Install(context.Background(), nil); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.runCalls) != 0 {
+		t.Fatalf("expected no calls, got %v", r.runCalls)
+	}
+}
+
+func TestPacmanIsInstalledTrue(t *testing.T) {
+	r := &fakeRunner{output: []byte("tio 3.2-1")}
+	p := NewPacman(r)
+	ok, err := p.IsInstalled(context.Background(), "tio")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ok {
+		t.Fatal("want installed=true")
+	}
+}
+
+func TestPacmanIsInstalledFalseOnError(t *testing.T) {
+	r := &fakeRunner{outputErr: errors.New("not found")}
+	p := NewPacman(r)
+	ok, err := p.IsInstalled(context.Background(), "ghost")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ok {
+		t.Fatal("want installed=false")
+	}
+}
+
+func TestPacmanUpdate(t *testing.T) {
+	r := &fakeRunner{}
+	p := NewPacman(r)
+	if err := p.Update(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	want := []string{"sudo", "pacman", "-Syu", "--noconfirm"}
+	if !reflect.DeepEqual(r.runCalls[0], want) {
+		t.Fatalf("args = %v, want %v", r.runCalls[0], want)
+	}
+}

internal/platform/pkgmgr.go

@@ -0,0 +1,20 @@
+package platform
+
+import "context"
+
+// PackageManager abstracts OS-level package operations so later plans
+// can add Debian/Fedora without touching modules.
+type PackageManager interface {
+	Name() string
+	IsInstalled(ctx context.Context, pkg string) (bool, error)
+	Install(ctx context.Context, pkgs []string) error
+	Reinstall(ctx context.Context, pkgs []string) error
+	Update(ctx context.Context) error
+}
+
+// Runner executes a command with arguments. Injected into package managers
+// so tests can stub shell-outs.
+type Runner interface {
+	Run(ctx context.Context, name string, args ...string) error
+	Output(ctx context.Context, name string, args ...string) ([]byte, error)
+}

internal/platform/platform.go

@@ -0,0 +1,63 @@
+// Package platform detects the host OS/distro/WSL status.
+package platform
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"strings"
+)
+
+// Distro is a narrow enum of distros we care about.
+type Distro string
+
+const (
+	DistroArch    Distro = "arch"
+	DistroUnknown Distro = "unknown"
+)
+
+// Platform holds detected host information.
+type Platform struct {
+	Distro Distro
+	IsWSL  bool
+	Arch   string // e.g. "amd64", "arm64"
+}
+
+// Detect reads the live system. Returns DistroUnknown rather than an error
+// when /etc/os-release is missing or unrecognized; callers decide what to do.
+func Detect() (Platform, error) {
+	f, err := os.Open("/etc/os-release")
+	distro := DistroUnknown
+	if err == nil {
+		distro = parseDistro(f)
+		_ = f.Close()
+	} else if !os.IsNotExist(err) {
+		return Platform{}, fmt.Errorf("open /etc/os-release: %w", err)
+	}
+
+	wsl := false
+	if data, err := os.ReadFile("/proc/sys/kernel/osrelease"); err == nil {
+		lower := strings.ToLower(string(data))
+		wsl = strings.Contains(lower, "microsoft") || strings.Contains(lower, "wsl")
+	}
+
+	return Platform{Distro: distro, IsWSL: wsl, Arch: runtime.GOARCH}, nil
+}
+
+func parseDistro(r io.Reader) Distro {
+	sc := bufio.NewScanner(r)
+	for sc.Scan() {
+		line := sc.Text()
+		if !strings.HasPrefix(line, "ID=") {
+			continue
+		}
+		id := strings.Trim(strings.TrimPrefix(line, "ID="), `"`)
+		if id == "arch" {
+			return DistroArch
+		}
+		return DistroUnknown
+	}
+	return DistroUnknown
+}

internal/platform/platform_test.go

@@ -0,0 +1,45 @@
+package platform
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseDistroArch(t *testing.T) {
+	osRelease := `NAME="Arch Linux"
+ID=arch
+ID_LIKE=archlinux
+`
+	if got := parseDistro(strings.NewReader(osRelease)); got != DistroArch {
+		t.Fatalf("got %v", got)
+	}
+}
+
+func TestParseDistroUbuntu(t *testing.T) {
+	osRelease := `NAME="Ubuntu"
+ID=ubuntu
+`
+	if got := parseDistro(strings.NewReader(osRelease)); got != DistroUnknown {
+		t.Fatalf("got %v", got)
+	}
+}
+
+func TestParseDistroQuoted(t *testing.T) {
+	osRelease := `ID="arch"
+`
+	if got := parseDistro(strings.NewReader(osRelease)); got != DistroArch {
+		t.Fatalf("got %v", got)
+	}
+}
+
+func TestDetectReturnsArch(t *testing.T) {
+	p, err := Detect()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p.Arch == "" {
+		t.Fatal("arch is empty")
+	}
+	// We don't assert Distro here because the test host may not be Arch.
+	// The parse-level tests above cover that logic.
+}

internal/platform/textblock.go

@@ -0,0 +1,78 @@
+package platform
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func blockMarkers(marker string) (string, string) {
+	return fmt.Sprintf("# >>> %s >>>", marker), fmt.Sprintf("# <<< %s <<<", marker)
+}
+
+// EnsureBlock writes a marker-delimited block into path. If the file does
+// not exist it is created. If a block with the same marker already exists
+// it is replaced in place. Surrounding content is preserved.
+func EnsureBlock(path, marker, content string) error {
+	start, end := blockMarkers(marker)
+	existing, err := os.ReadFile(path)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	block := start + "\n" + strings.TrimRight(content, "\n") + "\n" + end + "\n"
+
+	text := string(existing)
+	si := strings.Index(text, start)
+	ei := strings.Index(text, end)
+	if si >= 0 && ei > si {
+		endPos := ei + len(end)
+		if endPos < len(text) && text[endPos] == '\n' {
+			endPos++
+		}
+		text = text[:si] + block + text[endPos:]
+	} else {
+		if text != "" && !strings.HasSuffix(text, "\n") {
+			text += "\n"
+		}
+		text += block
+	}
+	return os.WriteFile(path, []byte(text), 0o644)
+}
+
+// HasBlock reports whether path contains a block with the given marker.
+// A missing file yields (false, nil).
+func HasBlock(path, marker string) (bool, error) {
+	start, _ := blockMarkers(marker)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false, nil
+		}
+		return false, err
+	}
+	return strings.Contains(string(data), start), nil
+}
+
+// RemoveBlock deletes a marker-delimited block if present.
+func RemoveBlock(path, marker string) error {
+	start, end := blockMarkers(marker)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	text := string(data)
+	si := strings.Index(text, start)
+	ei := strings.Index(text, end)
+	if si < 0 || ei <= si {
+		return nil
+	}
+	endPos := ei + len(end)
+	if endPos < len(text) && text[endPos] == '\n' {
+		endPos++
+	}
+	text = text[:si] + text[endPos:]
+	return os.WriteFile(path, []byte(text), 0o644)
+}

internal/platform/textblock_test.go

@@ -0,0 +1,88 @@
+package platform
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestEnsureBlockInsertsIntoMissingFile(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "rc")
+	if err := EnsureBlock(p, "archduino", "export FOO=1"); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(p)
+	want := "# >>> archduino >>>\nexport FOO=1\n# <<< archduino <<<\n"
+	if string(got) != want {
+		t.Fatalf("got %q want %q", got, want)
+	}
+}
+
+func TestEnsureBlockReplacesExisting(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "rc")
+	initial := "alias ll='ls -l'\n# >>> archduino >>>\nold content\n# <<< archduino <<<\necho tail\n"
+	if err := os.WriteFile(p, []byte(initial), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := EnsureBlock(p, "archduino", "new content"); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(p)
+	want := "alias ll='ls -l'\n# >>> archduino >>>\nnew content\n# <<< archduino <<<\necho tail\n"
+	if string(got) != want {
+		t.Fatalf("got %q want %q", got, want)
+	}
+}
+
+func TestEnsureBlockIdempotent(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "rc")
+	_ = EnsureBlock(p, "a", "x")
+	before, _ := os.ReadFile(p)
+	_ = EnsureBlock(p, "a", "x")
+	after, _ := os.ReadFile(p)
+	if string(before) != string(after) {
+		t.Fatalf("not idempotent: %q vs %q", before, after)
+	}
+}
+
+func TestHasBlockTrueFalse(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "rc")
+	has, err := HasBlock(p, "a")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if has {
+		t.Fatal("missing file should report has=false")
+	}
+	_ = os.WriteFile(p, []byte("no blocks here\n"), 0o644)
+	has, _ = HasBlock(p, "a")
+	if has {
+		t.Fatal("unblocked file should report has=false")
+	}
+	_ = EnsureBlock(p, "a", "x")
+	has, _ = HasBlock(p, "a")
+	if !has {
+		t.Fatal("blocked file should report has=true")
+	}
+}
+
+func TestRemoveBlock(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "rc")
+	_ = os.WriteFile(p, []byte("head\n# >>> a >>>\nmid\n# <<< a <<<\ntail\n"), 0o644)
+	if err := RemoveBlock(p, "a"); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(p)
+	if strings.Contains(string(got), ">>> a >>>") {
+		t.Fatalf("block not removed: %q", got)
+	}
+	if !strings.Contains(string(got), "head") || !strings.Contains(string(got), "tail") {
+		t.Fatalf("surrounding content lost: %q", got)
+	}
+}

internal/platform/writefile.go

@@ -0,0 +1,25 @@
+package platform
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// WriteUserFile writes data to path atomically (tmp + rename) with the
+// given mode, creating any missing parent directories (mode 0755).
+// Intended for user-owned destinations under $HOME — no sudo.
+func WriteUserFile(path string, data []byte, mode os.FileMode) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return err
+	}
+	tmp := path + ".tmp"
+	if err := os.WriteFile(tmp, data, mode); err != nil {
+		os.Remove(tmp)
+		return err
+	}
+	if err := os.Rename(tmp, path); err != nil {
+		os.Remove(tmp)
+		return err
+	}
+	return nil
+}

internal/platform/writefile_test.go

@@ -0,0 +1,54 @@
+package platform
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestWriteUserFileCreatesParent(t *testing.T) {
+	dir := t.TempDir()
+	dest := filepath.Join(dir, "a", "b", "c.txt")
+	if err := WriteUserFile(dest, []byte("hi"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(dest)
+	if string(got) != "hi" {
+		t.Fatalf("content %q", got)
+	}
+	info, _ := os.Stat(dest)
+	if info.Mode().Perm() != 0o644 {
+		t.Fatalf("mode %v", info.Mode().Perm())
+	}
+}
+
+func TestWriteUserFileOverwritesAtomically(t *testing.T) {
+	dir := t.TempDir()
+	dest := filepath.Join(dir, "x")
+	if err := WriteUserFile(dest, []byte("one"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := WriteUserFile(dest, []byte("two"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := os.ReadFile(dest)
+	if string(got) != "two" {
+		t.Fatalf("got %q want two", got)
+	}
+	// No .tmp sibling should be left behind.
+	if _, err := os.Stat(dest + ".tmp"); !os.IsNotExist(err) {
+		t.Fatalf(".tmp left behind: %v", err)
+	}
+}
+
+func TestWriteUserFileExecMode(t *testing.T) {
+	dir := t.TempDir()
+	dest := filepath.Join(dir, "bin")
+	if err := WriteUserFile(dest, []byte("#!/bin/sh\n"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	info, _ := os.Stat(dest)
+	if info.Mode().Perm() != 0o755 {
+		t.Fatalf("mode %v want 0755", info.Mode().Perm())
+	}
+}

internal/privilege/sudo.go

@@ -0,0 +1,82 @@
+// Package privilege manages sudo timestamp acquisition and keepalive so
+// a long-running installer only prompts once.
+package privilege
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"time"
+)
+
+// Keepalive holds the lifetime of a background sudo-refresh goroutine.
+type Keepalive struct {
+	cancel context.CancelFunc
+	done   chan struct{}
+}
+
+// Stop terminates the keepalive goroutine. Safe to call multiple times.
+func (k *Keepalive) Stop() {
+	if k == nil || k.cancel == nil {
+		return
+	}
+	k.cancel()
+	<-k.done
+	k.cancel = nil
+}
+
+// Acquirer abstracts the `sudo` binary so tests can inject a fake.
+type Acquirer interface {
+	Validate(ctx context.Context) error               // sudo -v (may prompt)
+	ValidateNonInteractive(ctx context.Context) error // sudo -n -v
+}
+
+// ExecSudo is the production Acquirer.
+type ExecSudo struct{}
+
+func (ExecSudo) Validate(ctx context.Context) error {
+	cmd := exec.CommandContext(ctx, "sudo", "-v")
+	// Connect to the real terminal so sudo can prompt for the password.
+	// exec.Cmd.Stdin defaults to /dev/null, not the parent process's stdin.
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}
+
+func (ExecSudo) ValidateNonInteractive(ctx context.Context) error {
+	return exec.CommandContext(ctx, "sudo", "-n", "-v").Run()
+}
+
+// Acquire runs `sudo -v` once (prompting if needed) and returns a Keepalive
+// that refreshes the timestamp every `interval` using ValidateNonInteractive.
+// If the initial Validate fails, no goroutine is started and the error is returned.
+func Acquire(ctx context.Context, a Acquirer, interval time.Duration) (*Keepalive, error) {
+	if a == nil {
+		a = ExecSudo{}
+	}
+	if interval <= 0 {
+		interval = 50 * time.Second
+	}
+	if err := a.Validate(ctx); err != nil {
+		return nil, fmt.Errorf("sudo -v failed: %w", err)
+	}
+	kCtx, cancel := context.WithCancel(ctx)
+	k := &Keepalive{cancel: cancel, done: make(chan struct{})}
+
+	go func() {
+		defer close(k.done)
+		t := time.NewTicker(interval)
+		defer t.Stop()
+		for {
+			select {
+			case <-kCtx.Done():
+				return
+			case <-t.C:
+				_ = a.ValidateNonInteractive(kCtx) // best-effort
+			}
+		}
+	}()
+	return k, nil
+}

internal/privilege/sudo_test.go

@@ -0,0 +1,65 @@
+package privilege
+
+import (
+	"context"
+	"errors"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+type fakeAcquirer struct {
+	validateErr error
+	validates   int32
+	refreshes   int32
+}
+
+func (f *fakeAcquirer) Validate(ctx context.Context) error {
+	atomic.AddInt32(&f.validates, 1)
+	return f.validateErr
+}
+func (f *fakeAcquirer) ValidateNonInteractive(ctx context.Context) error {
+	atomic.AddInt32(&f.refreshes, 1)
+	return nil
+}
+
+func TestAcquireFailsIfValidateFails(t *testing.T) {
+	a := &fakeAcquirer{validateErr: errors.New("wrong password")}
+	_, err := Acquire(context.Background(), a, 10*time.Millisecond)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+	if atomic.LoadInt32(&a.refreshes) != 0 {
+		t.Fatal("keepalive ran despite Validate failure")
+	}
+}
+
+func TestAcquireStartsKeepaliveAndStops(t *testing.T) {
+	a := &fakeAcquirer{}
+	k, err := Acquire(context.Background(), a, 5*time.Millisecond)
+	if err != nil {
+		t.Fatal(err)
+	}
+	time.Sleep(25 * time.Millisecond)
+	k.Stop()
+	got := atomic.LoadInt32(&a.refreshes)
+	if got < 2 {
+		t.Fatalf("refreshes = %d, want >= 2", got)
+	}
+
+	// After Stop, no additional refreshes should occur.
+	snap := atomic.LoadInt32(&a.refreshes)
+	time.Sleep(20 * time.Millisecond)
+	if after := atomic.LoadInt32(&a.refreshes); after != snap {
+		t.Fatalf("refreshes continued after Stop: %d → %d", snap, after)
+	}
+}
+
+func TestStopIsIdempotent(t *testing.T) {
+	k, err := Acquire(context.Background(), &fakeAcquirer{}, 5*time.Millisecond)
+	if err != nil {
+		t.Fatal(err)
+	}
+	k.Stop()
+	k.Stop() // must not panic or hang
+}

internal/state/state.go

@@ -0,0 +1,109 @@
+// Package state persists a per-run log used only for resume hints in the UI.
+// Correctness always comes from live Detect() calls.
+package state
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"time"
+)
+
+// RunRecord is the JSON document written to runs/<ts>.json.
+type RunRecord struct {
+	StartedAt time.Time      `json:"started_at"`
+	EndedAt   time.Time      `json:"ended_at"`
+	Modules   []ModuleRecord `json:"modules"`
+}
+
+// ModuleRecord captures how one module fared.
+type ModuleRecord struct {
+	ID       string    `json:"id"`
+	Status   string    `json:"status"` // succeeded|failed|skipped|planned
+	Duration string    `json:"duration"`
+	Error    string    `json:"error,omitempty"`
+	At       time.Time `json:"at"`
+}
+
+// Store is a file-backed run log.
+type Store struct {
+	Root string // e.g. ~/.local/state/archduino
+}
+
+// DefaultStore returns a Store rooted at $XDG_STATE_HOME/archduino or
+// ~/.local/state/archduino.
+func DefaultStore() (*Store, error) {
+	if xdg := os.Getenv("XDG_STATE_HOME"); xdg != "" {
+		return &Store{Root: filepath.Join(xdg, "archduino")}, nil
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return nil, err
+	}
+	return &Store{Root: filepath.Join(home, ".local", "state", "archduino")}, nil
+}
+
+// Save writes record as runs/<ts>.json and updates last.json. Both paths are
+// created if missing. Old runs beyond `keep` are deleted.
+func (s *Store) Save(rec RunRecord, keep int) error {
+	if keep <= 0 {
+		keep = 10
+	}
+	runsDir := filepath.Join(s.Root, "runs")
+	if err := os.MkdirAll(runsDir, 0o755); err != nil {
+		return err
+	}
+	name := rec.StartedAt.UTC().Format("20060102T150405Z") + ".json"
+	path := filepath.Join(runsDir, name)
+
+	data, err := json.MarshalIndent(rec, "", "  ")
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(path, data, 0o644); err != nil {
+		return err
+	}
+	if err := os.WriteFile(filepath.Join(s.Root, "last.json"), data, 0o644); err != nil {
+		return err
+	}
+	return rotate(runsDir, keep)
+}
+
+// LastRun reads last.json if present.
+func (s *Store) LastRun() (RunRecord, bool, error) {
+	data, err := os.ReadFile(filepath.Join(s.Root, "last.json"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return RunRecord{}, false, nil
+		}
+		return RunRecord{}, false, err
+	}
+	var rec RunRecord
+	if err := json.Unmarshal(data, &rec); err != nil {
+		return RunRecord{}, false, fmt.Errorf("parse last.json: %w", err)
+	}
+	return rec, true, nil
+}
+
+func rotate(dir string, keep int) error {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return err
+	}
+	names := make([]string, 0, len(entries))
+	for _, e := range entries {
+		if !e.IsDir() {
+			names = append(names, e.Name())
+		}
+	}
+	if len(names) <= keep {
+		return nil
+	}
+	sort.Strings(names) // lexicographic == chronological (UTC stamp)
+	for _, n := range names[:len(names)-keep] {
+		_ = os.Remove(filepath.Join(dir, n))
+	}
+	return nil
+}

internal/state/state_test.go

@@ -0,0 +1,63 @@
+package state
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func newStore(t *testing.T) *Store {
+	t.Helper()
+	return &Store{Root: t.TempDir()}
+}
+
+func TestSaveAndLoadLast(t *testing.T) {
+	s := newStore(t)
+	rec := RunRecord{
+		StartedAt: time.Date(2026, 4, 13, 10, 0, 0, 0, time.UTC),
+		EndedAt:   time.Date(2026, 4, 13, 10, 1, 0, 0, time.UTC),
+		Modules:   []ModuleRecord{{ID: "hello", Status: "succeeded", Duration: "1s"}},
+	}
+	if err := s.Save(rec, 10); err != nil {
+		t.Fatal(err)
+	}
+	got, ok, err := s.LastRun()
+	if err != nil || !ok {
+		t.Fatalf("LastRun err=%v ok=%v", err, ok)
+	}
+	if len(got.Modules) != 1 || got.Modules[0].ID != "hello" {
+		t.Fatalf("modules = %+v", got.Modules)
+	}
+}
+
+func TestLastRunMissingReturnsFalse(t *testing.T) {
+	s := newStore(t)
+	_, ok, err := s.LastRun()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ok {
+		t.Fatal("expected ok=false")
+	}
+}
+
+func TestRotateKeepsNewest(t *testing.T) {
+	s := newStore(t)
+	for i := 0; i < 12; i++ {
+		rec := RunRecord{
+			StartedAt: time.Date(2026, 1, 1, 0, 0, i, 0, time.UTC),
+			EndedAt:   time.Date(2026, 1, 1, 0, 0, i, 0, time.UTC),
+		}
+		if err := s.Save(rec, 5); err != nil {
+			t.Fatal(err)
+		}
+	}
+	entries, err := os.ReadDir(filepath.Join(s.Root, "runs"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 5 {
+		t.Fatalf("runs count = %d, want 5", len(entries))
+	}
+}

internal/subcommands/doctor/doctor.go

@@ -0,0 +1,104 @@
+// Package doctor reports module convergence and pinned-tool version drift.
+package doctor
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
+)
+
+// Run inspects every module in the registry plus pinned tool versions and
+// writes a human-readable report to w. Returns 0 when everything is
+// converged with no drift; 1 otherwise. Never panics on module errors.
+func Run(ctx context.Context, cfg config.Config, reg *module.Registry, runner platform.Runner, w io.Writer) int {
+	var converged, pending, errs, drift int
+
+	for _, m := range reg.All() {
+		id := m.Meta().ID
+		st, err := m.Detect(ctx)
+		if err != nil {
+			fmt.Fprintf(w, "[!] %s — detect failed: %v\n", id, err)
+			errs++
+			continue
+		}
+		pl, err := m.Plan(ctx, st)
+		if err != nil {
+			fmt.Fprintf(w, "[!] %s — plan failed: %v\n", id, err)
+			errs++
+			continue
+		}
+		if pl.IsEmpty() {
+			fmt.Fprintf(w, "[✓] %s\n", id)
+			converged++
+		} else {
+			fmt.Fprintf(w, "[✗] %s (%d actions pending)\n", id, len(pl.Actions))
+			pending++
+		}
+	}
+
+	drift += checkArduinoCLI(ctx, runner, cfg.ArduinoCLI.Version, w)
+	drift += checkWokwiCLI(ctx, runner, cfg.Renode.WokwiVersion, w)
+
+	fmt.Fprintf(w, "\n%d converged, %d need-install, %d drift, %d errors\n", converged, pending, drift, errs)
+
+	if pending > 0 || drift > 0 || errs > 0 {
+		return 1
+	}
+	return 0
+}
+
+type arduinoCLIVersion struct {
+	VersionString string `json:"VersionString"`
+}
+
+func checkArduinoCLI(ctx context.Context, runner platform.Runner, want string, w io.Writer) int {
+	if want == "" {
+		return 0
+	}
+	out, err := runner.Output(ctx, "arduino-cli", "version", "--format", "json")
+	if err != nil {
+		return 0 // not installed → silent skip
+	}
+	var v arduinoCLIVersion
+	if err := json.Unmarshal(out, &v); err != nil || v.VersionString == "" {
+		fmt.Fprintf(w, "[!] arduino-cli — version parse failed\n")
+		return 1
+	}
+	if v.VersionString != want {
+		fmt.Fprintf(w, "[!] arduino-cli drift: got %s, want %s\n", v.VersionString, want)
+		return 1
+	}
+	fmt.Fprintf(w, "[✓] arduino-cli %s\n", v.VersionString)
+	return 0
+}
+
+var wokwiVersionRE = regexp.MustCompile(`v?(\d+\.\d+\.\d+)`)
+
+func checkWokwiCLI(ctx context.Context, runner platform.Runner, want string, w io.Writer) int {
+	if want == "" {
+		return 0
+	}
+	out, err := runner.Output(ctx, "wokwi-cli", "--version")
+	if err != nil {
+		return 0
+	}
+	m := wokwiVersionRE.FindStringSubmatch(strings.TrimSpace(string(out)))
+	if len(m) < 2 {
+		fmt.Fprintf(w, "[!] wokwi-cli — version parse failed\n")
+		return 1
+	}
+	got := m[1]
+	if got != want {
+		fmt.Fprintf(w, "[!] wokwi-cli drift: got %s, want %s\n", got, want)
+		return 1
+	}
+	fmt.Fprintf(w, "[✓] wokwi-cli %s\n", got)
+	return 0
+}

internal/subcommands/doctor/doctor_test.go

@@ -0,0 +1,146 @@
+package doctor
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
+	"gitlab.hive-brain.de/MDietermann/Archduino/internal/module"
+)
+
+// convergedModule returns an empty Plan — always converged.
+type convergedModule struct{ id string }
+
+func (c convergedModule) Meta() module.Meta                            { return module.Meta{ID: c.id, Name: c.id} }
+func (c convergedModule) Detect(context.Context) (module.State, error) { return nil, nil }
+func (c convergedModule) Plan(context.Context, module.State) (module.Plan, error) {
+	return module.Plan{}, nil
+}
+func (c convergedModule) PlanForce(context.Context) (module.Plan, error) {
+	return module.Plan{}, nil
+}
+func (c convergedModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
+func (c convergedModule) Verify(context.Context) error                              { return nil }
+
+type pendingModule struct{ id string }
+
+func (p pendingModule) Meta() module.Meta                            { return module.Meta{ID: p.id} }
+func (p pendingModule) Detect(context.Context) (module.State, error) { return nil, nil }
+func (p pendingModule) Plan(context.Context, module.State) (module.Plan, error) {
+	return module.Plan{Actions: []module.Action{{Description: "do a thing"}}}, nil
+}
+func (p pendingModule) PlanForce(context.Context) (module.Plan, error) {
+	return module.Plan{Actions: []module.Action{{Description: "do a thing"}}}, nil
+}
+func (p pendingModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
+func (p pendingModule) Verify(context.Context) error                              { return nil }
+
+type detectFailModule struct{ id string }
+
+func (d detectFailModule) Meta() module.Meta { return module.Meta{ID: d.id} }
+func (d detectFailModule) Detect(context.Context) (module.State, error) {
+	return nil, errors.New("boom")
+}
+func (d detectFailModule) Plan(context.Context, module.State) (module.Plan, error) {
+	return module.Plan{}, nil
+}
+func (d detectFailModule) PlanForce(context.Context) (module.Plan, error) {
+	return module.Plan{}, nil
+}
+func (d detectFailModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
+func (d detectFailModule) Verify(context.Context) error                              { return nil }
+
+// notFoundRunner simulates "command not found" for version checks.
+type notFoundRunner struct{}
+
+func (notFoundRunner) Run(context.Context, string, ...string) error { return errors.New("not found") }
+func (notFoundRunner) Output(context.Context, string, ...string) ([]byte, error) {
+	return nil, errors.New("not found")
+}
+
+// fixedRunner returns a preset version string for a matching command.
+type fixedRunner struct {
+	arduinoOut []byte
+	arduinoErr error
+	wokwiOut   []byte
+	wokwiErr   error
+}
+
+func (f fixedRunner) Run(context.Context, string, ...string) error { return nil }
+func (f fixedRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
+	switch name {
+	case "arduino-cli":
+		return f.arduinoOut, f.arduinoErr
+	case "wokwi-cli":
+		return f.wokwiOut, f.wokwiErr
+	}
+	return nil, errors.New("no match")
+}
+
+func TestDoctorAllConvergedExitsZero(t *testing.T) {
+	reg := module.NewRegistry()
+	_ = reg.Register(convergedModule{id: "foo"})
+	var buf bytes.Buffer
+	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
+	if code != 0 {
+		t.Fatalf("exit %d, want 0; output:\n%s", code, buf.String())
+	}
+	if !strings.Contains(buf.String(), "[✓] foo") {
+		t.Errorf("missing converged mark: %s", buf.String())
+	}
+}
+
+func TestDoctorDivergedExitsOne(t *testing.T) {
+	reg := module.NewRegistry()
+	_ = reg.Register(pendingModule{id: "bar"})
+	var buf bytes.Buffer
+	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
+	if code != 1 {
+		t.Fatalf("exit %d, want 1", code)
+	}
+	if !strings.Contains(buf.String(), "[✗] bar") {
+		t.Errorf("missing diverged mark: %s", buf.String())
+	}
+}
+
+func TestDoctorDetectErrorIsReported(t *testing.T) {
+	reg := module.NewRegistry()
+	_ = reg.Register(detectFailModule{id: "baz"})
+	var buf bytes.Buffer
+	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
+	if code != 1 {
+		t.Fatalf("exit %d, want 1", code)
+	}
+	if !strings.Contains(buf.String(), "[!] baz") {
+		t.Errorf("missing error mark: %s", buf.String())
+	}
+}
+
+func TestDoctorArduinoCLIDriftIsReported(t *testing.T) {
+	reg := module.NewRegistry()
+	_ = reg.Register(convergedModule{id: "foo"})
+	cfg := config.Config{ArduinoCLI: config.ArduinoCLIConfig{Version: "0.35.3"}}
+	runner := fixedRunner{arduinoOut: []byte(`{"VersionString":"0.36.0"}`)}
+	var buf bytes.Buffer
+	code := Run(context.Background(), cfg, reg, runner, &buf)
+	if code != 1 {
+		t.Fatalf("exit %d, want 1 (drift)", code)
+	}
+	if !strings.Contains(buf.String(), "drift") {
+		t.Errorf("missing drift report: %s", buf.String())
+	}
+}
+
+func TestDoctorMissingBinariesSkipVersionCheck(t *testing.T) {
+	reg := module.NewRegistry()
+	_ = reg.Register(convergedModule{id: "foo"})
+	cfg := config.Config{ArduinoCLI: config.ArduinoCLIConfig{Version: "0.35.3"}}
+	var buf bytes.Buffer
+	code := Run(context.Background(), cfg, reg, notFoundRunner{}, &buf)
+	if code != 0 {
+		t.Fatalf("exit %d, want 0; output:\n%s", code, buf.String())
+	}
+}

internal/subcommands/newproject/assets/default.ino

@@ -0,0 +1,9 @@
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) { ; }
+  Serial.println("Hello from Arduino!");
+}
+
+void loop() {
+  // Your code here
+}

internal/subcommands/newproject/assets/esp32.ino

@@ -0,0 +1,22 @@
+#include <WiFi.h>
+
+const char* ssid = "YOUR_SSID";
+const char* password = "YOUR_PASS";
+
+void setup() {
+  Serial.begin(115200);
+  delay(1000);
+  WiFi.begin(ssid, password);
+  Serial.print("Connecting to WiFi");
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println();
+  Serial.print("Connected! IP: ");
+  Serial.println(WiFi.localIP());
+}
+
+void loop() {
+  delay(1000);
+}

internal/subcommands/newproject/assets/esp32s3.ino

@@ -0,0 +1,9 @@
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) { ; }
+  Serial.println("Hello from Arduino!");
+}
+
+void loop() {
+  // Your code here
+}

internal/subcommands/newproject/assets/esp8266.ino

@@ -0,0 +1,22 @@
+#include <ESP8266WiFi.h>
+
+const char* ssid = "YOUR_SSID";
+const char* password = "YOUR_PASS";
+
+void setup() {
+  Serial.begin(115200);
+  delay(1000);
+  WiFi.begin(ssid, password);
+  Serial.print("Connecting to WiFi");
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println();
+  Serial.print("Connected! IP: ");
+  Serial.println(WiFi.localIP());
+}
+
+void loop() {
+  delay(1000);
+}

internal/subcommands/newproject/assets/mega.ino

@@ -0,0 +1,9 @@
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) { ; }
+  Serial.println("Hello from Arduino!");
+}
+
+void loop() {
+  // Your code here
+}