feat(cli): Add /model command for interactive model selection (#8940)

Co-authored-by: Miguel Solorio <miguel.solorio07@gmail.com>

packages/cli/src/ui/hooks/useModelCommand.test.ts

@@ -0,0 +1,42 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { renderHook, act } from '@testing-library/react';
+import { useModelCommand } from './useModelCommand.js';
+
+describe('useModelCommand', () => {
+  it('should initialize with the model dialog closed', () => {
+    const { result } = renderHook(() => useModelCommand());
+    expect(result.current.isModelDialogOpen).toBe(false);
+  });
+
+  it('should open the model dialog when openModelDialog is called', () => {
+    const { result } = renderHook(() => useModelCommand());
+
+    act(() => {
+      result.current.openModelDialog();
+    });
+
+    expect(result.current.isModelDialogOpen).toBe(true);
+  });
+
+  it('should close the model dialog when closeModelDialog is called', () => {
+    const { result } = renderHook(() => useModelCommand());
+
+    // Open it first
+    act(() => {
+      result.current.openModelDialog();
+    });
+    expect(result.current.isModelDialogOpen).toBe(true);
+
+    // Then close it
+    act(() => {
+      result.current.closeModelDialog();
+    });
+    expect(result.current.isModelDialogOpen).toBe(false);
+  });
+});