feat(tui): add NvChadTheme field and ThemeByID helper

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")
+	}
+}