feat: Add markdown toggle (alt+m) to switch between rendered and raw… (#10383)

Co-authored-by: Jacob Richman <jacob314@gmail.com>

packages/cli/src/ui/components/messages/GeminiMessage.test.tsx

@@ -0,0 +1,49 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { GeminiMessage } from './GeminiMessage.js';
+import { StreamingState } from '../../types.js';
+import { renderWithProviders } from '../../../test-utils/render.js';
+
+describe('<GeminiMessage /> - Raw Markdown Display Snapshots', () => {
+  const baseProps = {
+    text: 'Test **bold** and `code` markdown\n\n```javascript\nconst x = 1;\n```',
+    isPending: false,
+    terminalWidth: 80,
+  };
+
+  it.each([
+    { renderMarkdown: true, description: '(default)' },
+    {
+      renderMarkdown: false,
+      description: '(raw markdown with syntax highlighting, no line numbers)',
+    },
+  ])(
+    'renders with renderMarkdown=$renderMarkdown $description',
+    ({ renderMarkdown }) => {
+      const { lastFrame } = renderWithProviders(
+        <GeminiMessage {...baseProps} />,
+        {
+          uiState: { renderMarkdown, streamingState: StreamingState.Idle },
+        },
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    },
+  );
+
+  it.each([{ renderMarkdown: true }, { renderMarkdown: false }])(
+    'renders pending state with renderMarkdown=$renderMarkdown',
+    ({ renderMarkdown }) => {
+      const { lastFrame } = renderWithProviders(
+        <GeminiMessage {...baseProps} isPending={true} />,
+        {
+          uiState: { renderMarkdown, streamingState: StreamingState.Idle },
+        },
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    },
+  );
+});