feat(ui): implement refreshed UX for Composer layout (#21212)

Co-authored-by: Keith Guerin <keithguerin@gmail.com>

packages/cli/src/ui/components/AppHeader.test.tsx

@@ -8,6 +8,7 @@ import {
   renderWithProviders,
   persistentStateMock,
 } from '../../test-utils/render.js';
+import type { LoadedSettings } from '../../config/settings.js';
 import { AppHeader } from './AppHeader.js';
 import { describe, it, expect, vi } from 'vitest';
 import { makeFakeConfig } from '@google/gemini-cli-core';
@@ -264,4 +265,23 @@ describe('<AppHeader />', () => {
     expect(lastFrame()).toMatchSnapshot();
     unmount();
   });
+
+  it('should NOT render Tips when ui.hideTips is true', async () => {
+    const mockConfig = makeFakeConfig();
+    const { lastFrame, waitUntilReady, unmount } = await renderWithProviders(
+      <AppHeader version="1.0.0" />,
+      {
+        config: mockConfig,
+        settings: {
+          merged: {
+            ui: { hideTips: true },
+          },
+        } as unknown as LoadedSettings,
+      },
+    );
+    await waitUntilReady();
+
+    expect(lastFrame()).not.toContain('Tips');
+    unmount();
+  });
 });