debugging(ui): add optional debugRainbow setting

docs/reference/configuration.md

@@ -202,6 +202,12 @@ their corresponding top-level category object in your `settings.json` file.
 
 #### `ui`
 
+- **`ui.debugRainbow`** (boolean):
+  - **Description:** Enable debug rainbow rendering. Only useful for debugging
+    rendering bugs and performance issues.
+  - **Default:** `false`
+  - **Requires restart:** Yes
+
 - **`ui.theme`** (string):
   - **Description:** The color theme for the UI. See the CLI themes guide for
     available options.

packages/cli/src/config/settingsSchema.ts

@@ -439,6 +439,16 @@ const SETTINGS_SCHEMA = {
     description: 'User interface settings.',
     showInDialog: false,
     properties: {
+      debugRainbow: {
+        type: 'boolean',
+        label: 'Debug Rainbow',
+        category: 'UI',
+        requiresRestart: true,
+        default: false,
+        description:
+          'Enable debug rainbow rendering. Only useful for debugging rendering bugs and performance issues.',
+        showInDialog: false,
+      },
       theme: {
         type: 'string',
         label: 'Theme',

packages/cli/src/interactiveCli.tsx

@@ -163,6 +163,7 @@ export async function startInteractiveUI(
         settings.merged.ui.incrementalRendering !== false &&
         useAlternateBuffer &&
         !isShpool,
+      debugRainbow: settings.merged.ui.debugRainbow === true,
     },
   );
 

schemas/settings.schema.json

@@ -230,6 +230,13 @@
       "default": {},
       "type": "object",
       "properties": {
+        "debugRainbow": {
+          "title": "Debug Rainbow",
+          "description": "Enable debug rainbow rendering. Only useful for debugging rendering bugs and performance issues.",
+          "markdownDescription": "Enable debug rainbow rendering. Only useful for debugging rendering bugs and performance issues.\n\n- Category: `UI`\n- Requires restart: `yes`\n- Default: `false`",
+          "default": false,
+          "type": "boolean"
+        },
         "theme": {
           "title": "Theme",
           "description": "The color theme for the UI. See the CLI themes guide for available options.",