feat(theming): integrate NvChad chadrc rewrite into Apply

internal/modules/neovim/neovim_test.go

@@ -177,4 +177,34 @@ func TestUnknownThemeFallsBackToFirst(t *testing.T) {
 	}
 }
 
+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{}