Merge Plan 4a: theme/new/doctor subcommands + theming package

cmd/archduino/main.go

@@ -2,12 +2,14 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"
 
+	"github.com/charmbracelet/huh"
 	"github.com/spf13/cobra"
 
 	"github.com/MDietermann/ArduinoArchSetup/internal/config"
@@ -28,6 +30,9 @@ import (
 	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
 	"github.com/MDietermann/ArduinoArchSetup/internal/privilege"
 	"github.com/MDietermann/ArduinoArchSetup/internal/state"
+	"github.com/MDietermann/ArduinoArchSetup/internal/subcommands/doctor"
+	"github.com/MDietermann/ArduinoArchSetup/internal/subcommands/newproject"
+	"github.com/MDietermann/ArduinoArchSetup/internal/theming"
 	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
 	"github.com/MDietermann/ArduinoArchSetup/internal/tui/dashboard"
 	"github.com/MDietermann/ArduinoArchSetup/internal/tui/wizard"
@@ -57,7 +62,7 @@ func buildRegistry(cfg config.Config, themeID string) (*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),
+		neovim.New(cfg.Neovim, themeID, pm, git),
 		renode.New(cfg.Renode, pm, yay),
 	}
 	for _, m := range mods {
@@ -77,6 +82,9 @@ func main() {
 		Version:       version,
 	}
 	root.AddCommand(newInstallCmd())
+	root.AddCommand(newThemeCmd())
+	root.AddCommand(newNewCmd())
+	root.AddCommand(newDoctorCmd())
 
 	// Wire SIGINT/SIGTERM to a cancellable context so long-running phases
 	// (engine.Run, sudo keepalive) observe the cancellation promptly.
@@ -147,8 +155,9 @@ func newInstallCmd() *cobra.Command {
 
 			started := time.Now().UTC()
 			var (
-				sum    engine.Summary
+				sum           engine.Summary
-				runErr error
+				runErr        error
+				selectedTheme = cfg.ThemeOverrides["__active"]
 			)
 
 			if noTUI || dryRun {
@@ -194,6 +203,9 @@ func newInstallCmd() *cobra.Command {
 				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)
 			}
@@ -203,6 +215,14 @@ func newInstallCmd() *cobra.Command {
 				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 {
@@ -296,3 +316,109 @@ func writeState(started, ended time.Time, sum engine.Summary) error {
 	}
 	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
+}

internal/config/config.go

@@ -61,6 +61,16 @@ type RenodeConfig struct {
 	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"`
@@ -76,6 +86,7 @@ type Config struct {
 	ShellConfig     ShellConfigSection `yaml:"shell_config"`
 	Neovim          NeovimConfig       `yaml:"neovim"`
 	Renode          RenodeConfig       `yaml:"renode"`
+	Scaffolding     Scaffolding        `yaml:"scaffolding"`
 }
 
 const currentVersion = 1
@@ -161,5 +172,8 @@ func merge(base, over Config) Config {
 	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

@@ -108,3 +108,26 @@ func TestLoadRejectsUnknownVersion(t *testing.T) {
 		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

@@ -97,3 +97,12 @@ renode:
     - 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/modules/neovim/neovim.go

@@ -17,12 +17,19 @@ import (
 	"github.com/MDietermann/ArduinoArchSetup/internal/config"
 	"github.com/MDietermann/ArduinoArchSetup/internal/module"
 	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
-	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
+	"github.com/MDietermann/ArduinoArchSetup/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 {
@@ -40,14 +47,13 @@ var assetMap = []struct {
 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 {
+func New(cfg config.NeovimConfig, themeID string, pm platform.PackageManager, git platform.GitClient) Module {
-	return Module{cfg: cfg, themeID: themeID, themes: themes, pm: pm, git: git}
+	return Module{cfg: cfg, themeID: themeID, pm: pm, git: git}
 }
 
 type state struct {
@@ -79,13 +85,48 @@ func nvimCfg() (string, error) {
 }
 
 func (m Module) resolvedTheme() string {
-	if t, ok := tui.ThemeByID(m.themes, m.themeID); ok && t.NvChadTheme != "" {
+	if t, ok := theming.Get(m.themeID); ok {
 		return t.NvChadTheme
 	}
-	if len(m.themes) > 0 {
+	return theming.Default().NvChadTheme
-		return m.themes[0].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
 	}
-	return "gruvbox"
+	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) {

internal/modules/neovim/neovim_test.go

@@ -10,7 +10,6 @@ import (
 	"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 {
@@ -58,7 +57,7 @@ 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})
+	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)
@@ -81,7 +80,7 @@ func TestDetectNonNvChadTriggersBackup(t *testing.T) {
 	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})
+	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")
@@ -92,7 +91,7 @@ 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})
+	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 {
@@ -150,7 +149,7 @@ 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})
+	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{})
@@ -161,20 +160,51 @@ func TestPlanAfterApplyIsEmpty(t *testing.T) {
 	}
 }
 
-func TestUnknownThemeFallsBackToFirst(t *testing.T) {
+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", tui.BuiltinThemes, platform.NewPacman(r), platform.GitClient{Runner: r})
+	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")
+	}
+}
+
 var _ module.Module = Module{}

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"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/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 +1,135 @@
+package doctor
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/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) 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) 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) 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
+}

internal/subcommands/newproject/assets/nano.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/uno.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/newproject.go

@@ -0,0 +1,75 @@
+// Package newproject scaffolds a new Arduino sketch directory.
+package newproject
+
+import (
+	"embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
+)
+
+//go:embed assets
+var assetsFS embed.FS
+
+const clangdContent = `CompileFlags:
+  Add:
+    - -xc++
+    - -std=c++17
+`
+
+// Run creates a new Arduino project directory. It errors if the project
+// directory already exists, if the board is unknown, or if the project name
+// contains a path separator.
+func Run(cfg config.Config, project, board string) error {
+	if project == "" {
+		return fmt.Errorf("project name required")
+	}
+	if strings.ContainsAny(project, "/\\") || strings.HasPrefix(project, ".") {
+		return fmt.Errorf("invalid project name %q", project)
+	}
+
+	var b *config.Board
+	var valid []string
+	for i := range cfg.Scaffolding.Boards {
+		bp := &cfg.Scaffolding.Boards[i]
+		valid = append(valid, bp.Name)
+		if bp.Name == board {
+			b = bp
+		}
+	}
+	if b == nil {
+		return fmt.Errorf("unknown board %q; valid: %s", board, strings.Join(valid, ", "))
+	}
+
+	if _, err := os.Stat(project); err == nil {
+		return fmt.Errorf("project directory %q already exists", project)
+	}
+	if err := os.MkdirAll(project, 0o755); err != nil {
+		return err
+	}
+
+	// Pick .ino template: try <template>.ino, else default.ino.
+	inoData, err := assetsFS.ReadFile(filepath.Join("assets", b.Template+".ino"))
+	if err != nil {
+		inoData, err = assetsFS.ReadFile("assets/default.ino")
+		if err != nil {
+			return err
+		}
+	}
+	if err := platform.WriteUserFile(filepath.Join(project, project+".ino"), inoData, 0o644); err != nil {
+		return err
+	}
+
+	sketch := fmt.Sprintf("default_fqbn: %s\ndefault_port: auto\n", b.FQBN)
+	if err := platform.WriteUserFile(filepath.Join(project, "sketch.yaml"), []byte(sketch), 0o644); err != nil {
+		return err
+	}
+	if err := platform.WriteUserFile(filepath.Join(project, ".clangd"), []byte(clangdContent), 0o644); err != nil {
+		return err
+	}
+	return nil
+}

internal/subcommands/newproject/newproject_test.go

@@ -0,0 +1,84 @@
+package newproject
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+)
+
+func sampleCfg() config.Config {
+	return config.Config{
+		Scaffolding: config.Scaffolding{Boards: []config.Board{
+			{Name: "uno", FQBN: "arduino:avr:uno", Template: "uno"},
+			{Name: "xyz", FQBN: "fake:fqbn:xyz", Template: "does-not-exist"},
+		}},
+	}
+}
+
+func TestRunCreatesProject(t *testing.T) {
+	dir := t.TempDir()
+	t.Chdir(dir)
+	if err := Run(sampleCfg(), "blinky", "uno"); err != nil {
+		t.Fatal(err)
+	}
+	ino, err := os.ReadFile(filepath.Join("blinky", "blinky.ino"))
+	if err != nil {
+		t.Fatalf("blinky.ino missing: %v", err)
+	}
+	if len(ino) == 0 {
+		t.Error("blinky.ino empty")
+	}
+	sketch, err := os.ReadFile(filepath.Join("blinky", "sketch.yaml"))
+	if err != nil {
+		t.Fatalf("sketch.yaml missing: %v", err)
+	}
+	if !strings.Contains(string(sketch), "arduino:avr:uno") {
+		t.Errorf("sketch.yaml missing fqbn: %s", sketch)
+	}
+	if _, err := os.Stat(filepath.Join("blinky", ".clangd")); err != nil {
+		t.Errorf(".clangd missing: %v", err)
+	}
+}
+
+func TestRunRefusesExistingDir(t *testing.T) {
+	dir := t.TempDir()
+	t.Chdir(dir)
+	os.Mkdir("blinky", 0o755)
+	if err := Run(sampleCfg(), "blinky", "uno"); err == nil {
+		t.Fatal("want error on existing dir")
+	}
+}
+
+func TestRunFallsBackToDefaultTemplate(t *testing.T) {
+	dir := t.TempDir()
+	t.Chdir(dir)
+	if err := Run(sampleCfg(), "thing", "xyz"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(filepath.Join("thing", "thing.ino")); err != nil {
+		t.Fatalf("thing.ino missing: %v", err)
+	}
+}
+
+func TestRunUnknownBoardErrors(t *testing.T) {
+	dir := t.TempDir()
+	t.Chdir(dir)
+	err := Run(sampleCfg(), "thing", "bogus")
+	if err == nil {
+		t.Fatal("want error")
+	}
+	if !strings.Contains(err.Error(), "uno") {
+		t.Errorf("error should list valid boards: %v", err)
+	}
+}
+
+func TestRunRejectsSlashInProjectName(t *testing.T) {
+	dir := t.TempDir()
+	t.Chdir(dir)
+	if err := Run(sampleCfg(), "bad/name", "uno"); err == nil {
+		t.Fatal("want error on slashes")
+	}
+}

internal/theming/assets/catppuccin/lazygit.yml

@@ -0,0 +1,13 @@
+gui:
+  theme:
+    activeBorderColor:
+      - "#f9e2af"
+      - bold
+    inactiveBorderColor:
+      - "#585b70"
+    selectedLineBgColor:
+      - "#313244"
+    cherryPickedCommitFgColor:
+      - "#a6e3a1"
+    defaultFgColor:
+      - "#cdd6f4"

internal/theming/assets/catppuccin/starship.toml

@@ -0,0 +1,26 @@
+palette = "catppuccin_mocha"
+format = """$directory$git_branch$git_status$character"""
+
+[directory]
+style = "bold fg:bright-yellow"
+truncation_length = 3
+
+[git_branch]
+style = "bold fg:bright-green"
+format = " [$branch]($style) "
+
+[git_status]
+style = "bold fg:bright-red"
+
+[character]
+success_symbol = "[❯](bold fg:bright-green)"
+error_symbol = "[❯](bold fg:bright-red)"
+
+[palettes.catppuccin_mocha]
+bright-yellow = "#f9e2af"
+bright-green = "#a6e3a1"
+bright-red = "#f38ba8"
+bright-blue = "#89b4fa"
+bright-purple = "#cba6f7"
+bright-aqua = "#94e2d5"
+bright-orange = "#fab387"

internal/theming/assets/catppuccin/theme.yaml

@@ -0,0 +1,2 @@
+display_name: "Catppuccin Mocha"
+nvchad: "catppuccin"

internal/theming/assets/catppuccin/yazi.toml

@@ -0,0 +1,30 @@
+[manager]
+cwd = { fg = "#f9e2af" }
+tab_active = { fg = "#1e1e2e", bg = "#f9e2af" }
+tab_inactive = { fg = "#bac2de", bg = "#313244" }
+border_symbol = "│"
+border_style = { fg = "#585b70" }
+count_copied = { fg = "#1e1e2e", bg = "#a6e3a1" }
+count_cut = { fg = "#1e1e2e", bg = "#f38ba8" }
+count_selected = { fg = "#1e1e2e", bg = "#f9e2af" }
+
+[status]
+separator_open = ""
+separator_close = ""
+mode_normal = { fg = "#1e1e2e", bg = "#a6e3a1", bold = true }
+mode_select = { fg = "#1e1e2e", bg = "#f9e2af", bold = true }
+mode_unset = { fg = "#1e1e2e", bg = "#f38ba8", bold = true }
+progress_label = { fg = "#cdd6f4", bold = true }
+progress_normal = { fg = "#89b4fa", bg = "#313244" }
+progress_error = { fg = "#f38ba8", bg = "#313244" }
+
+[input]
+border = { fg = "#f9e2af" }
+title = {}
+value = {}
+selected = { reversed = true }
+
+[select]
+border = { fg = "#f9e2af" }
+active = { fg = "#a6e3a1", bold = true }
+inactive = {}

internal/theming/assets/catppuccin/zellij.kdl

@@ -0,0 +1,35 @@
+theme "catppuccin-mocha"
+default_layout "default"
+default_mode "normal"
+pane_frames false
+simplified_ui true
+mouse_mode false
+
+keybinds {
+    shared {
+        bind "Alt h" { MoveFocusOrTab "Left"; }
+        bind "Alt l" { MoveFocusOrTab "Right"; }
+        bind "Alt j" { MoveFocus "Down"; }
+        bind "Alt k" { MoveFocus "Up"; }
+        bind "Alt n" { NewPane "Down"; }
+        bind "Alt v" { NewPane "Right"; }
+        bind "Alt f" { ToggleFloatingPanes; }
+        bind "Alt t" { NewTab; }
+    }
+}
+
+themes {
+    catppuccin-mocha {
+        fg "#cdd6f4"
+        bg "#1e1e2e"
+        black "#181825"
+        red "#f38ba8"
+        green "#a6e3a1"
+        yellow "#f9e2af"
+        blue "#89b4fa"
+        magenta "#cba6f7"
+        cyan "#94e2d5"
+        white "#bac2de"
+        orange "#fab387"
+    }
+}

internal/theming/assets/dracula/lazygit.yml

@@ -0,0 +1,13 @@
+gui:
+  theme:
+    activeBorderColor:
+      - "#f1fa8c"
+      - bold
+    inactiveBorderColor:
+      - "#6272a4"
+    selectedLineBgColor:
+      - "#44475a"
+    cherryPickedCommitFgColor:
+      - "#50fa7b"
+    defaultFgColor:
+      - "#f8f8f2"

internal/theming/assets/dracula/starship.toml

@@ -0,0 +1,26 @@
+palette = "dracula"
+format = """$directory$git_branch$git_status$character"""
+
+[directory]
+style = "bold fg:bright-yellow"
+truncation_length = 3
+
+[git_branch]
+style = "bold fg:bright-green"
+format = " [$branch]($style) "
+
+[git_status]
+style = "bold fg:bright-red"
+
+[character]
+success_symbol = "[❯](bold fg:bright-green)"
+error_symbol = "[❯](bold fg:bright-red)"
+
+[palettes.dracula]
+bright-yellow = "#f1fa8c"
+bright-green = "#50fa7b"
+bright-red = "#ff5555"
+bright-blue = "#bd93f9"
+bright-purple = "#ff79c6"
+bright-aqua = "#8be9fd"
+bright-orange = "#ffb86c"

internal/theming/assets/dracula/theme.yaml

@@ -0,0 +1,2 @@
+display_name: "Dracula"
+nvchad: "dracula"

internal/theming/assets/dracula/yazi.toml

@@ -0,0 +1,30 @@
+[manager]
+cwd = { fg = "#f1fa8c" }
+tab_active = { fg = "#282a36", bg = "#f1fa8c" }
+tab_inactive = { fg = "#bfbfbf", bg = "#44475a" }
+border_symbol = "│"
+border_style = { fg = "#6272a4" }
+count_copied = { fg = "#282a36", bg = "#50fa7b" }
+count_cut = { fg = "#282a36", bg = "#ff5555" }
+count_selected = { fg = "#282a36", bg = "#f1fa8c" }
+
+[status]
+separator_open = ""
+separator_close = ""
+mode_normal = { fg = "#282a36", bg = "#50fa7b", bold = true }
+mode_select = { fg = "#282a36", bg = "#f1fa8c", bold = true }
+mode_unset = { fg = "#282a36", bg = "#ff5555", bold = true }
+progress_label = { fg = "#f8f8f2", bold = true }
+progress_normal = { fg = "#bd93f9", bg = "#44475a" }
+progress_error = { fg = "#ff5555", bg = "#44475a" }
+
+[input]
+border = { fg = "#f1fa8c" }
+title = {}
+value = {}
+selected = { reversed = true }
+
+[select]
+border = { fg = "#f1fa8c" }
+active = { fg = "#50fa7b", bold = true }
+inactive = {}

internal/theming/assets/dracula/zellij.kdl

@@ -0,0 +1,35 @@
+theme "dracula"
+default_layout "default"
+default_mode "normal"
+pane_frames false
+simplified_ui true
+mouse_mode false
+
+keybinds {
+    shared {
+        bind "Alt h" { MoveFocusOrTab "Left"; }
+        bind "Alt l" { MoveFocusOrTab "Right"; }
+        bind "Alt j" { MoveFocus "Down"; }
+        bind "Alt k" { MoveFocus "Up"; }
+        bind "Alt n" { NewPane "Down"; }
+        bind "Alt v" { NewPane "Right"; }
+        bind "Alt f" { ToggleFloatingPanes; }
+        bind "Alt t" { NewTab; }
+    }
+}
+
+themes {
+    dracula {
+        fg "#f8f8f2"
+        bg "#282a36"
+        black "#21222c"
+        red "#ff5555"
+        green "#50fa7b"
+        yellow "#f1fa8c"
+        blue "#bd93f9"
+        magenta "#ff79c6"
+        cyan "#8be9fd"
+        white "#bfbfbf"
+        orange "#ffb86c"
+    }
+}

internal/theming/assets/gruvbox/lazygit.yml

@@ -0,0 +1,13 @@
+gui:
+  theme:
+    activeBorderColor:
+      - "#fabd2f"
+      - bold
+    inactiveBorderColor:
+      - "#665c54"
+    selectedLineBgColor:
+      - "#3c3836"
+    cherryPickedCommitFgColor:
+      - "#b8bb26"
+    defaultFgColor:
+      - "#ebdbb2"

internal/theming/assets/gruvbox/starship.toml

@@ -0,0 +1,26 @@
+palette = "gruvbox_dark"
+format = """$directory$git_branch$git_status$character"""
+
+[directory]
+style = "bold fg:bright-yellow"
+truncation_length = 3
+
+[git_branch]
+style = "bold fg:bright-green"
+format = " [$branch]($style) "
+
+[git_status]
+style = "bold fg:bright-red"
+
+[character]
+success_symbol = "[❯](bold fg:bright-green)"
+error_symbol = "[❯](bold fg:bright-red)"
+
+[palettes.gruvbox_dark]
+bright-yellow = "#fabd2f"
+bright-green = "#b8bb26"
+bright-red = "#fb4934"
+bright-blue = "#83a598"
+bright-purple = "#d3869b"
+bright-aqua = "#8ec07c"
+bright-orange = "#fe8019"

internal/theming/assets/gruvbox/theme.yaml

@@ -0,0 +1,2 @@
+display_name: "Gruvbox Dark"
+nvchad: "gruvbox"

internal/theming/assets/gruvbox/yazi.toml

@@ -0,0 +1,30 @@
+[manager]
+cwd = { fg = "#fabd2f" }
+tab_active = { fg = "#282828", bg = "#fabd2f" }
+tab_inactive = { fg = "#a89984", bg = "#3c3836" }
+border_symbol = "│"
+border_style = { fg = "#665c54" }
+count_copied = { fg = "#282828", bg = "#b8bb26" }
+count_cut = { fg = "#282828", bg = "#fb4934" }
+count_selected = { fg = "#282828", bg = "#fabd2f" }
+
+[status]
+separator_open = ""
+separator_close = ""
+mode_normal = { fg = "#282828", bg = "#b8bb26", bold = true }
+mode_select = { fg = "#282828", bg = "#fabd2f", bold = true }
+mode_unset = { fg = "#282828", bg = "#fb4934", bold = true }
+progress_label = { fg = "#ebdbb2", bold = true }
+progress_normal = { fg = "#458588", bg = "#3c3836" }
+progress_error = { fg = "#fb4934", bg = "#3c3836" }
+
+[input]
+border = { fg = "#fabd2f" }
+title = {}
+value = {}
+selected = { reversed = true }
+
+[select]
+border = { fg = "#fabd2f" }
+active = { fg = "#b8bb26", bold = true }
+inactive = {}

internal/theming/assets/gruvbox/zellij.kdl

@@ -0,0 +1,35 @@
+theme "gruvbox-dark"
+default_layout "default"
+default_mode "normal"
+pane_frames false
+simplified_ui true
+mouse_mode false
+
+keybinds {
+    shared {
+        bind "Alt h" { MoveFocusOrTab "Left"; }
+        bind "Alt l" { MoveFocusOrTab "Right"; }
+        bind "Alt j" { MoveFocus "Down"; }
+        bind "Alt k" { MoveFocus "Up"; }
+        bind "Alt n" { NewPane "Down"; }
+        bind "Alt v" { NewPane "Right"; }
+        bind "Alt f" { ToggleFloatingPanes; }
+        bind "Alt t" { NewTab; }
+    }
+}
+
+themes {
+    gruvbox-dark {
+        fg "#ebdbb2"
+        bg "#282828"
+        black "#1d2021"
+        red "#cc241d"
+        green "#98971a"
+        yellow "#d79921"
+        blue "#458588"
+        magenta "#b16286"
+        cyan "#689d6a"
+        white "#a89984"
+        orange "#d65d0e"
+    }
+}

internal/theming/assets/nord/lazygit.yml

@@ -0,0 +1,13 @@
+gui:
+  theme:
+    activeBorderColor:
+      - "#ebcb8b"
+      - bold
+    inactiveBorderColor:
+      - "#4c566a"
+    selectedLineBgColor:
+      - "#3b4252"
+    cherryPickedCommitFgColor:
+      - "#a3be8c"
+    defaultFgColor:
+      - "#d8dee9"

internal/theming/assets/nord/starship.toml

@@ -0,0 +1,26 @@
+palette = "nord"
+format = """$directory$git_branch$git_status$character"""
+
+[directory]
+style = "bold fg:bright-yellow"
+truncation_length = 3
+
+[git_branch]
+style = "bold fg:bright-green"
+format = " [$branch]($style) "
+
+[git_status]
+style = "bold fg:bright-red"
+
+[character]
+success_symbol = "[❯](bold fg:bright-green)"
+error_symbol = "[❯](bold fg:bright-red)"
+
+[palettes.nord]
+bright-yellow = "#ebcb8b"
+bright-green = "#a3be8c"
+bright-red = "#bf616a"
+bright-blue = "#81a1c1"
+bright-purple = "#b48ead"
+bright-aqua = "#88c0d0"
+bright-orange = "#d08770"

internal/theming/assets/nord/theme.yaml

@@ -0,0 +1,2 @@
+display_name: "Nord"
+nvchad: "nord"

internal/theming/assets/nord/yazi.toml

@@ -0,0 +1,30 @@
+[manager]
+cwd = { fg = "#ebcb8b" }
+tab_active = { fg = "#2e3440", bg = "#ebcb8b" }
+tab_inactive = { fg = "#e5e9f0", bg = "#3b4252" }
+border_symbol = "│"
+border_style = { fg = "#4c566a" }
+count_copied = { fg = "#2e3440", bg = "#a3be8c" }
+count_cut = { fg = "#2e3440", bg = "#bf616a" }
+count_selected = { fg = "#2e3440", bg = "#ebcb8b" }
+
+[status]
+separator_open = ""
+separator_close = ""
+mode_normal = { fg = "#2e3440", bg = "#a3be8c", bold = true }
+mode_select = { fg = "#2e3440", bg = "#ebcb8b", bold = true }
+mode_unset = { fg = "#2e3440", bg = "#bf616a", bold = true }
+progress_label = { fg = "#d8dee9", bold = true }
+progress_normal = { fg = "#81a1c1", bg = "#3b4252" }
+progress_error = { fg = "#bf616a", bg = "#3b4252" }
+
+[input]
+border = { fg = "#ebcb8b" }
+title = {}
+value = {}
+selected = { reversed = true }
+
+[select]
+border = { fg = "#ebcb8b" }
+active = { fg = "#a3be8c", bold = true }
+inactive = {}

internal/theming/assets/nord/zellij.kdl

@@ -0,0 +1,35 @@
+theme "nord"
+default_layout "default"
+default_mode "normal"
+pane_frames false
+simplified_ui true
+mouse_mode false
+
+keybinds {
+    shared {
+        bind "Alt h" { MoveFocusOrTab "Left"; }
+        bind "Alt l" { MoveFocusOrTab "Right"; }
+        bind "Alt j" { MoveFocus "Down"; }
+        bind "Alt k" { MoveFocus "Up"; }
+        bind "Alt n" { NewPane "Down"; }
+        bind "Alt v" { NewPane "Right"; }
+        bind "Alt f" { ToggleFloatingPanes; }
+        bind "Alt t" { NewTab; }
+    }
+}
+
+themes {
+    nord {
+        fg "#d8dee9"
+        bg "#2e3440"
+        black "#3b4252"
+        red "#bf616a"
+        green "#a3be8c"
+        yellow "#ebcb8b"
+        blue "#81a1c1"
+        magenta "#b48ead"
+        cyan "#88c0d0"
+        white "#e5e9f0"
+        orange "#d08770"
+    }
+}

internal/theming/assets/tokyonight/lazygit.yml

@@ -0,0 +1,13 @@
+gui:
+  theme:
+    activeBorderColor:
+      - "#e0af68"
+      - bold
+    inactiveBorderColor:
+      - "#3b4261"
+    selectedLineBgColor:
+      - "#283457"
+    cherryPickedCommitFgColor:
+      - "#9ece6a"
+    defaultFgColor:
+      - "#c0caf5"

internal/theming/assets/tokyonight/starship.toml

@@ -0,0 +1,26 @@
+palette = "tokyonight"
+format = """$directory$git_branch$git_status$character"""
+
+[directory]
+style = "bold fg:bright-yellow"
+truncation_length = 3
+
+[git_branch]
+style = "bold fg:bright-green"
+format = " [$branch]($style) "
+
+[git_status]
+style = "bold fg:bright-red"
+
+[character]
+success_symbol = "[❯](bold fg:bright-green)"
+error_symbol = "[❯](bold fg:bright-red)"
+
+[palettes.tokyonight]
+bright-yellow = "#e0af68"
+bright-green = "#9ece6a"
+bright-red = "#f7768e"
+bright-blue = "#7aa2f7"
+bright-purple = "#bb9af7"
+bright-aqua = "#7dcfff"
+bright-orange = "#ff9e64"

internal/theming/assets/tokyonight/theme.yaml

@@ -0,0 +1,2 @@
+display_name: "Tokyo Night"
+nvchad: "tokyonight"

internal/theming/assets/tokyonight/yazi.toml

@@ -0,0 +1,30 @@
+[manager]
+cwd = { fg = "#e0af68" }
+tab_active = { fg = "#1a1b26", bg = "#e0af68" }
+tab_inactive = { fg = "#a9b1d6", bg = "#283457" }
+border_symbol = "│"
+border_style = { fg = "#3b4261" }
+count_copied = { fg = "#1a1b26", bg = "#9ece6a" }
+count_cut = { fg = "#1a1b26", bg = "#f7768e" }
+count_selected = { fg = "#1a1b26", bg = "#e0af68" }
+
+[status]
+separator_open = ""
+separator_close = ""
+mode_normal = { fg = "#1a1b26", bg = "#9ece6a", bold = true }
+mode_select = { fg = "#1a1b26", bg = "#e0af68", bold = true }
+mode_unset = { fg = "#1a1b26", bg = "#f7768e", bold = true }
+progress_label = { fg = "#c0caf5", bold = true }
+progress_normal = { fg = "#7aa2f7", bg = "#283457" }
+progress_error = { fg = "#f7768e", bg = "#283457" }
+
+[input]
+border = { fg = "#e0af68" }
+title = {}
+value = {}
+selected = { reversed = true }
+
+[select]
+border = { fg = "#e0af68" }
+active = { fg = "#9ece6a", bold = true }
+inactive = {}

internal/theming/assets/tokyonight/zellij.kdl

@@ -0,0 +1,35 @@
+theme "tokyonight"
+default_layout "default"
+default_mode "normal"
+pane_frames false
+simplified_ui true
+mouse_mode false
+
+keybinds {
+    shared {
+        bind "Alt h" { MoveFocusOrTab "Left"; }
+        bind "Alt l" { MoveFocusOrTab "Right"; }
+        bind "Alt j" { MoveFocus "Down"; }
+        bind "Alt k" { MoveFocus "Up"; }
+        bind "Alt n" { NewPane "Down"; }
+        bind "Alt v" { NewPane "Right"; }
+        bind "Alt f" { ToggleFloatingPanes; }
+        bind "Alt t" { NewTab; }
+    }
+}
+
+themes {
+    tokyonight {
+        fg "#c0caf5"
+        bg "#1a1b26"
+        black "#15161e"
+        red "#f7768e"
+        green "#9ece6a"
+        yellow "#e0af68"
+        blue "#7aa2f7"
+        magenta "#bb9af7"
+        cyan "#7dcfff"
+        white "#a9b1d6"
+        orange "#ff9e64"
+    }
+}

internal/theming/theming.go

@@ -0,0 +1,224 @@
+// Package theming applies a selected colorscheme across starship, zellij,
+// yazi, lazygit, and NvChad. Themes are discovered from embedded manifest
+// files under assets/<id>/theme.yaml at package init time.
+package theming
+
+import (
+	"embed"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
+	"gopkg.in/yaml.v3"
+)
+
+// ChadrcWriter is the hook used by Apply to rewrite NvChad's chadrc.lua
+// after a theme change. The neovim module registers its WriteChadrc here
+// via an init() function to avoid a theming→neovim import cycle (neovim
+// now imports theming to look up the NvChad theme name). If nil, Apply
+// skips the chadrc update silently.
+var ChadrcWriter func(nvChadThemeName string) error
+
+//go:embed assets
+var assetsFS embed.FS
+
+// Theme describes a colorscheme discovered under assets/<id>/theme.yaml.
+type Theme struct {
+	ID          string
+	DisplayName string
+	NvChadTheme string
+}
+
+type manifest struct {
+	DisplayName string `yaml:"display_name"`
+	NvChad      string `yaml:"nvchad"`
+}
+
+var discovered []Theme
+
+func init() {
+	themes, err := discover()
+	if err != nil {
+		// Package is embed-only; discovery failure is a programmer error,
+		// not runtime input. Panic so tests surface the mistake early.
+		panic(fmt.Errorf("theming: discover themes: %w", err))
+	}
+	discovered = themes
+}
+
+func discover() ([]Theme, error) {
+	entries, err := fs.ReadDir(assetsFS, "assets")
+	if err != nil {
+		return nil, err
+	}
+	var out []Theme
+	for _, e := range entries {
+		if !e.IsDir() {
+			continue
+		}
+		id := e.Name()
+		m, err := readManifest(id)
+		if err != nil {
+			return nil, fmt.Errorf("theme %q: %w", id, err)
+		}
+		out = append(out, Theme{ID: id, DisplayName: m.DisplayName, NvChadTheme: m.NvChad})
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].ID < out[j].ID })
+	return out, nil
+}
+
+func readManifest(id string) (manifest, error) {
+	data, err := assetsFS.ReadFile(filepath.Join("assets", id, "theme.yaml"))
+	if err != nil {
+		return manifest{}, err
+	}
+	var m manifest
+	if err := yaml.Unmarshal(data, &m); err != nil {
+		return manifest{}, err
+	}
+	if m.DisplayName == "" {
+		return manifest{}, fmt.Errorf("empty display_name")
+	}
+	if m.NvChad == "" {
+		return manifest{}, fmt.Errorf("empty nvchad")
+	}
+	return m, nil
+}
+
+// List returns the themes sorted by ID.
+func List() []Theme {
+	out := make([]Theme, len(discovered))
+	copy(out, discovered)
+	return out
+}
+
+// Default returns the archduino default theme. Used by the wizard's fresh-
+// install default and by callers that resolve an unknown theme ID.
+// The identity here is stable policy: gruvbox is the project's long-standing
+// default (carried over from the pre-Go installer). Changing this changes
+// the out-of-box experience on fresh systems.
+func Default() Theme {
+	if t, ok := Get("gruvbox"); ok {
+		return t
+	}
+	if len(discovered) > 0 {
+		return discovered[0]
+	}
+	return Theme{ID: "gruvbox", DisplayName: "Gruvbox Dark", NvChadTheme: "gruvbox"}
+}
+
+// Get returns the theme with the given ID, if present.
+func Get(id string) (Theme, bool) {
+	for _, t := range discovered {
+		if t.ID == id {
+			return t, true
+		}
+	}
+	return Theme{}, false
+}
+
+// toolConfig describes one tool's config file: its asset name under
+// assets/<theme>/ and its user-config destination relative to $HOME.
+type toolConfig struct {
+	Asset   string // e.g. "starship.toml"
+	DestRel string // e.g. ".config/starship.toml"
+}
+
+var toolConfigs = []toolConfig{
+	{"starship.toml", ".config/starship.toml"},
+	{"zellij.kdl", ".config/zellij/config.kdl"},
+	{"yazi.toml", ".config/yazi/theme.toml"},
+	{"lazygit.yml", ".config/lazygit/config.yml"},
+}
+
+// Apply writes each tool's theme config to the user's home directory.
+// Task 3 adds overlay-file update; Task 4 adds NvChad chadrc rewrite.
+func Apply(cfg config.Config, themeID string) error {
+	th, ok := Get(themeID)
+	if !ok {
+		ids := make([]string, 0, len(discovered))
+		for _, t := range discovered {
+			ids = append(ids, t.ID)
+		}
+		return fmt.Errorf("unknown theme %q; valid: %s", themeID, strings.Join(ids, ", "))
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return err
+	}
+
+	for _, tc := range toolConfigs {
+		data, err := assetsFS.ReadFile(filepath.Join("assets", th.ID, tc.Asset))
+		if err != nil {
+			return fmt.Errorf("read asset %s: %w", tc.Asset, err)
+		}
+		dst := filepath.Join(home, tc.DestRel)
+		if err := platform.WriteUserFile(dst, data, 0o644); err != nil {
+			return fmt.Errorf("write %s: %w", tc.DestRel, err)
+		}
+	}
+	_ = cfg // overlay carries config state; overlay file update below
+	if err := updateOverlayActive(th.ID); err != nil {
+		return fmt.Errorf("update overlay: %w", err)
+	}
+
+	if ChadrcWriter != nil {
+		if err := ChadrcWriter(th.NvChadTheme); err != nil {
+			return fmt.Errorf("update chadrc: %w", err)
+		}
+	}
+
+	// Clear NvChad's base46 theme cache so the new theme activates on next
+	// nvim launch. Errors ignored — the cache may not exist.
+	_ = os.RemoveAll(filepath.Join(home, ".cache", "nvim", "base46"))
+	_ = os.RemoveAll(filepath.Join(home, ".local", "share", "nvim", "lazy", "base46", "lua", "base46", "themes"))
+	return nil
+}
+
+// updateOverlayActive rewrites ~/.config/archduino/overlay.yaml so that
+// theme_overrides.__active reflects the selected theme, preserving all
+// other keys via a generic map round-trip.
+func updateOverlayActive(themeID string) error {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return err
+	}
+	path := filepath.Join(home, ".config", "archduino", "overlay.yaml")
+
+	var root map[string]any
+	if data, err := os.ReadFile(path); err == nil {
+		if err := yaml.Unmarshal(data, &root); err != nil {
+			return fmt.Errorf("parse overlay: %w", err)
+		}
+	}
+	if root == nil {
+		root = map[string]any{}
+	}
+
+	if _, ok := root["version"]; !ok {
+		root["version"] = 1
+	}
+
+	var overrides map[string]any
+	if raw, ok := root["theme_overrides"]; ok {
+		if m, ok := raw.(map[string]any); ok {
+			overrides = m
+		}
+	}
+	if overrides == nil {
+		overrides = map[string]any{}
+	}
+	overrides["__active"] = themeID
+	root["theme_overrides"] = overrides
+
+	out, err := yaml.Marshal(root)
+	if err != nil {
+		return err
+	}
+	return platform.WriteUserFile(path, out, 0o644)
+}

internal/theming/theming_test.go

@@ -0,0 +1,200 @@
+package theming
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+)
+
+func TestListDiscoversThemes(t *testing.T) {
+	themes := List()
+	if len(themes) == 0 {
+		t.Fatal("no themes discovered")
+	}
+	for _, th := range themes {
+		if th.ID == "" || th.DisplayName == "" || th.NvChadTheme == "" {
+			t.Errorf("incomplete theme: %+v", th)
+		}
+	}
+}
+
+func TestGetKnownThemeReturnsMatch(t *testing.T) {
+	got, ok := Get("gruvbox")
+	if !ok {
+		t.Fatal("gruvbox should exist")
+	}
+	if got.ID != "gruvbox" || got.DisplayName == "" || got.NvChadTheme != "gruvbox" {
+		t.Fatalf("got %+v", got)
+	}
+}
+
+func TestGetUnknownThemeReturnsFalse(t *testing.T) {
+	if _, ok := Get("does-not-exist"); ok {
+		t.Fatal("bogus id should return ok=false")
+	}
+}
+
+func TestListIsSortedByID(t *testing.T) {
+	themes := List()
+	for i := 1; i < len(themes); i++ {
+		if themes[i].ID < themes[i-1].ID {
+			t.Fatalf("not sorted: %s before %s", themes[i-1].ID, themes[i].ID)
+		}
+	}
+}
+
+func TestApplyWritesFourToolConfigs(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	if err := Apply(config.Config{}, "gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+
+	checks := []struct{ rel, wantPrefix string }{
+		{".config/starship.toml", "palette"},
+		{".config/zellij/config.kdl", "theme"},
+		{".config/yazi/theme.toml", ""},
+		{".config/lazygit/config.yml", "gui"},
+	}
+	for _, c := range checks {
+		data, err := os.ReadFile(filepath.Join(home, c.rel))
+		if err != nil {
+			t.Errorf("%s missing: %v", c.rel, err)
+			continue
+		}
+		if len(data) == 0 {
+			t.Errorf("%s empty", c.rel)
+		}
+		if c.wantPrefix != "" && !strings.HasPrefix(strings.TrimSpace(string(data)), c.wantPrefix) {
+			t.Errorf("%s: want prefix %q, got %q", c.rel, c.wantPrefix, string(data[:min(len(data), 40)]))
+		}
+	}
+}
+
+func TestApplyUnknownThemeErrors(t *testing.T) {
+	if err := Apply(config.Config{}, "does-not-exist"); err == nil {
+		t.Fatal("want error on unknown theme")
+	}
+}
+
+func TestApplyUpdatesOverlayActive(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	if err := Apply(config.Config{}, "gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+	data, err := os.ReadFile(filepath.Join(home, ".config", "archduino", "overlay.yaml"))
+	if err != nil {
+		t.Fatalf("overlay missing: %v", err)
+	}
+	if !strings.Contains(string(data), "__active: gruvbox") {
+		t.Fatalf("overlay missing active theme: %s", data)
+	}
+}
+
+func TestApplyPreservesOtherOverlayKeys(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	op := filepath.Join(home, ".config", "archduino", "overlay.yaml")
+	if err := os.MkdirAll(filepath.Dir(op), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(op, []byte("version: 1\nextra_packages:\n  - foo\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := Apply(config.Config{}, "gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+	data, _ := os.ReadFile(op)
+	if !strings.Contains(string(data), "- foo") {
+		t.Fatalf("extra_packages lost: %s", data)
+	}
+	if !strings.Contains(string(data), "__active: gruvbox") {
+		t.Fatalf("active theme missing after preserve: %s", data)
+	}
+}
+
+func TestApplyRewritesChadrcIfPresent(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	nvimCfg := filepath.Join(home, ".config", "nvim", "lua")
+	if err := os.MkdirAll(nvimCfg, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(nvimCfg, "chadrc.lua"),
+		[]byte(`M.base46 = { theme = "onedark" }`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	// The real ChadrcWriter lives in the neovim package, which cannot be
+	// imported here without creating an import cycle (neovim→theming).
+	// Stub it with a minimal writer that covers what the test asserts.
+	prev := ChadrcWriter
+	t.Cleanup(func() { ChadrcWriter = prev })
+	ChadrcWriter = func(name string) error {
+		return os.WriteFile(filepath.Join(nvimCfg, "chadrc.lua"),
+			[]byte(`theme = "`+name+`"`), 0o644)
+	}
+
+	if err := Apply(config.Config{}, "gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+	data, _ := os.ReadFile(filepath.Join(nvimCfg, "chadrc.lua"))
+	if !strings.Contains(string(data), `theme = "gruvbox"`) {
+		t.Fatalf("chadrc not rewritten: %s", data)
+	}
+	if strings.Contains(string(data), `theme = "onedark"`) {
+		t.Fatalf("old theme still present: %s", data)
+	}
+}
+
+func TestApplyNoChadrcIsFine(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	if err := Apply(config.Config{}, "gruvbox"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestAllFiveThemesPresent(t *testing.T) {
+	want := []string{"catppuccin", "dracula", "gruvbox", "nord", "tokyonight"}
+	themes := List()
+	if len(themes) != len(want) {
+		t.Fatalf("want %d themes, got %d", len(want), len(themes))
+	}
+	for i, id := range want {
+		if themes[i].ID != id {
+			t.Fatalf("themes[%d].ID = %q, want %q", i, themes[i].ID, id)
+		}
+	}
+}
+
+func TestApplyEachThemeWritesStarship(t *testing.T) {
+	for _, id := range []string{"catppuccin", "dracula", "nord", "tokyonight"} {
+		id := id
+		t.Run(id, func(t *testing.T) {
+			home := t.TempDir()
+			t.Setenv("HOME", home)
+			if err := Apply(config.Config{}, id); err != nil {
+				t.Fatal(err)
+			}
+			data, err := os.ReadFile(filepath.Join(home, ".config", "starship.toml"))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(data) == 0 {
+				t.Fatal("empty starship.toml")
+			}
+		})
+	}
+}
+
+func TestDefaultIsGruvbox(t *testing.T) {
+	if got := Default(); got.ID != "gruvbox" {
+		t.Fatalf("Default().ID = %q, want gruvbox", got.ID)
+	}
+}

internal/tui/state.go

@@ -5,35 +5,15 @@ import (
 
 	"github.com/MDietermann/ArduinoArchSetup/internal/config"
 	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/internal/theming"
 )
 
-// Theme is a named colorscheme presented in the wizard. Each entry carries
+// Theme is a named colorscheme presented in the wizard. It is a thin
-// per-tool theme names; Plan 3b uses NvChadTheme, later plans add more.
+// display value for the dropdown; the authoritative theme catalogue lives
+// in the theming package (theming.List / theming.Get).
 type Theme struct {
-	ID          string
+	ID   string
-	Name        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", 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.
@@ -74,7 +54,7 @@ func NewWizardState(cfg config.Config, reg *module.Registry) WizardState {
 	}
 	sort.Slice(choices, func(i, j int) bool { return choices[i].ID < choices[j].ID })
 
-	theme := BuiltinThemes[0].ID
+	theme := theming.Default().ID
 	if override, ok := cfg.ThemeOverrides["__active"]; ok && override != "" {
 		theme = override
 	}

internal/tui/state_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/MDietermann/ArduinoArchSetup/internal/config"
 	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/internal/theming"
 )
 
 type fakeModule struct{ id, name, desc string }
@@ -34,7 +35,7 @@ func TestNewWizardStatePreTicksAllByDefault(t *testing.T) {
 			t.Errorf("%s not selected", m.ID)
 		}
 	}
-	if s.ThemeID != BuiltinThemes[0].ID {
+	if s.ThemeID != theming.Default().ID {
 		t.Errorf("theme = %q", s.ThemeID)
 	}
 }
@@ -71,30 +72,3 @@ func TestSelectedIDsOnlyReturnsChecked(t *testing.T) {
 	}
 }
 
-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")
-	}
-}

internal/tui/wizard/wizard.go

@@ -10,6 +10,7 @@ import (
 	"github.com/charmbracelet/huh"
 
 	"github.com/MDietermann/ArduinoArchSetup/internal/module"
+	"github.com/MDietermann/ArduinoArchSetup/internal/theming"
 	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
 )
 
@@ -23,9 +24,10 @@ func Run(ctx context.Context, reg *module.Registry, initial tui.WizardState) (tu
 		return s, false, nil
 	}
 
-	themeOptions := make([]huh.Option[string], 0, len(tui.BuiltinThemes))
+	themes := theming.List()
-	for _, t := range tui.BuiltinThemes {
+	themeOptions := make([]huh.Option[string], 0, len(themes))
-		themeOptions = append(themeOptions, huh.NewOption(t.Name, t.ID))
+	for _, t := range themes {
+		themeOptions = append(themeOptions, huh.NewOption(t.DisplayName, t.ID))
 	}
 
 	moduleOptions := make([]huh.Option[string], 0, len(s.Modules))