Merge Plan 3b: neovim + renode modules + theme plumbing

cmd/archduino/main.go

@@ -16,7 +16,9 @@ import (
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/arduinocli"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/fonts"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/gittools"
+	"github.com/MDietermann/ArduinoArchSetup/internal/modules/neovim"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/packages"
+	"github.com/MDietermann/ArduinoArchSetup/internal/modules/renode"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/shellconfig"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/starship"
 	"github.com/MDietermann/ArduinoArchSetup/internal/modules/themes"
@@ -37,7 +39,7 @@ var version = "dev"
 // 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) (*module.Registry, error) {
+func buildRegistry(cfg config.Config, themeID string) (*module.Registry, error) {
 	reg := module.NewRegistry()
 	runner := platform.ExecRunner{}
 	pm := platform.NewPacman(runner)
@@ -55,6 +57,8 @@ func buildRegistry(cfg config.Config) (*module.Registry, error) {
 		themes.New(cfg.Themes),
 		arduinocli.New(cfg.ArduinoCLI, runner),
 		shellconfig.New(cfg.ShellConfig),
+		neovim.New(cfg.Neovim, themeID, tui.BuiltinThemes, pm, git),
+		renode.New(cfg.Renode, pm, yay),
 	}
 	for _, m := range mods {
 		if err := reg.Register(m); err != nil {
@@ -122,7 +126,7 @@ func newInstallCmd() *cobra.Command {
 				return err
 			}
 
-			reg, err := buildRegistry(cfg)
+			reg, err := buildRegistry(cfg, "")
 			if err != nil {
 				return fmt.Errorf("build registry: %w", err)
 			}
@@ -183,6 +187,13 @@ func newInstallCmd() *cobra.Command {
 					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)
+				}
 				// Either the CLI flag or the wizard toggle can force halt-on-error.
 				sum, runErr = dashboard.Run(ctx, reg, finalState, halt || finalState.HaltOnError)
 			}

internal/config/config.go

@@ -45,6 +45,22 @@ 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"`
+}
+
 // Config is the fully-resolved runtime configuration.
 type Config struct {
 	Version         int                `yaml:"version"`
@@ -58,6 +74,8 @@ type Config struct {
 	Zellij          ZellijConfig       `yaml:"zellij"`
 	Themes          ThemesConfig       `yaml:"themes"`
 	ShellConfig     ShellConfigSection `yaml:"shell_config"`
+	Neovim          NeovimConfig       `yaml:"neovim"`
+	Renode          RenodeConfig       `yaml:"renode"`
 }
 
 const currentVersion = 1
@@ -137,5 +155,11 @@ func merge(base, over Config) Config {
 	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
+	}
 	return out
 }

internal/config/config_test.go

@@ -73,6 +73,31 @@ func TestDefaultsCarryModuleInputs(t *testing.T) {
 	}
 }
 
+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")

internal/config/defaults.yaml

@@ -80,3 +80,20 @@ shell_config:
         alias v="nvim"
         alias y="yazi"
         alias theme="archduino-theme"
+
+neovim:
+  nvchad_starter_repo: "https://github.com/NvChad/starter"
+
+renode:
+  wokwi_version: "0.28.1"
+  wokwi_url: "https://github.com/wokwi/wokwi-cli/releases/download/v0.28.1/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"

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 +1,422 @@
+// 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"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
+	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
+)
+
+//go:embed assets/*
+var assets embed.FS
+
+// 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
+	themes  []tui.Theme
+	pm      platform.PackageManager
+	git     platform.GitClient
+}
+
+// New constructs a Neovim Module.
+func New(cfg config.NeovimConfig, themeID string, themes []tui.Theme, pm platform.PackageManager, git platform.GitClient) Module {
+	return Module{cfg: cfg, themeID: themeID, themes: themes, 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 := tui.ThemeByID(m.themes, m.themeID); ok && t.NvChadTheme != "" {
+		return t.NvChadTheme
+	}
+	if len(m.themes) > 0 {
+		return m.themes[0].NvChadTheme
+	}
+	return "gruvbox"
+}
+
+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
+}

internal/modules/neovim/neovim_test.go

@@ -0,0 +1,180 @@
+package neovim
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
+	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
+)
+
+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", tui.BuiltinThemes, 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", tui.BuiltinThemes, 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", tui.BuiltinThemes, 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", tui.BuiltinThemes, 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 TestUnknownThemeFallsBackToFirst(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", tui.BuiltinThemes, 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"))
+	if !strings.Contains(string(chadrc), `theme = "gruvbox"`) {
+		t.Fatalf("fallback theme not applied: %s", chadrc)
+	}
+}
+
+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 +1,187 @@
+// 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"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/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
+}

internal/modules/renode/renode_test.go

@@ -0,0 +1,145 @@
+package renode
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/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)
+	}
+}
+
+var _ module.Module = Module{}

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/tui/state.go

@@ -7,21 +7,33 @@ import (
 	"github.com/MDietermann/ArduinoArchSetup/internal/module"
 )
 
-// Theme is a named colorscheme presented in the wizard. Plan 3 wires these
-// names to actual theme modules; for now they are display-only strings.
+// Theme is a named colorscheme presented in the wizard. Each entry carries
+// per-tool theme names; Plan 3b uses NvChadTheme, later plans add more.
 type Theme struct {
-	ID   string
-	Name string
+	ID          string
+	Name        string
+	NvChadTheme string
 }
 
 // BuiltinThemes is the fixed list the wizard shows. Keep in sync with the
 // themes shipped by Plan 3's theme module.
 var BuiltinThemes = []Theme{
-	{ID: "gruvbox", Name: "Gruvbox Dark"},
-	{ID: "catppuccin", Name: "Catppuccin Mocha"},
-	{ID: "tokyonight", Name: "Tokyo Night"},
-	{ID: "nord", Name: "Nord"},
-	{ID: "dracula", Name: "Dracula"},
+	{ID: "gruvbox", Name: "Gruvbox Dark", NvChadTheme: "gruvbox"},
+	{ID: "catppuccin", Name: "Catppuccin Mocha", NvChadTheme: "catppuccin"},
+	{ID: "tokyonight", Name: "Tokyo Night", NvChadTheme: "tokyonight"},
+	{ID: "nord", Name: "Nord", NvChadTheme: "nord"},
+	{ID: "dracula", Name: "Dracula", NvChadTheme: "dracula"},
+}
+
+// ThemeByID returns the Theme with the given ID. The bool is false when no
+// match is found; callers decide whether to fall back or error.
+func ThemeByID(themes []Theme, id string) (Theme, bool) {
+	for _, t := range themes {
+		if t.ID == id {
+			return t, true
+		}
+	}
+	return Theme{}, false
 }
 
 // ModuleChoice is one row in the module selector.

internal/tui/state_test.go

@@ -70,3 +70,31 @@ func TestSelectedIDsOnlyReturnsChecked(t *testing.T) {
 		t.Fatalf("got %v", got)
 	}
 }
+
+func TestBuiltinThemesCarryNvChadName(t *testing.T) {
+	for _, th := range BuiltinThemes {
+		if th.NvChadTheme == "" {
+			t.Errorf("theme %q has empty NvChadTheme", th.ID)
+		}
+	}
+}
+
+func TestThemeByIDReturnsMatch(t *testing.T) {
+	got, ok := ThemeByID(BuiltinThemes, "dracula")
+	if !ok {
+		t.Fatal("dracula should exist")
+	}
+	if got.ID != "dracula" {
+		t.Fatalf("got id=%q", got.ID)
+	}
+	if got.NvChadTheme == "" {
+		t.Fatal("NvChadTheme empty")
+	}
+}
+
+func TestThemeByIDFallsBackWhenUnknown(t *testing.T) {
+	_, ok := ThemeByID(BuiltinThemes, "does-not-exist")
+	if ok {
+		t.Fatal("unknown id should report ok=false")
+	}
+}