feat: initial implementation of Light Chat app with React, Capacitor, and comprehensive tests

src/App.test.jsx

@@ -0,0 +1,40 @@
+import { describe, it, expect, vi } from 'vitest'
+import { render, screen, fireEvent, waitFor } from '@testing-library/react'
+import App from './App.jsx'
+
+// Mock only the components, not the hook
+vi.mock('./components/ChatWindow.jsx', () => ({
+  ChatWindow: () => <div data-testid="chat-window">ChatWindow Mock</div>
+}))
+
+vi.mock('./components/SessionDrawer.jsx', () => ({
+  SessionDrawer: ({ isOpen }) => isOpen ? <div data-testid="session-drawer">SessionDrawer Mock</div> : null
+}))
+
+describe('App', () => {
+  it('should render app with menu button', async () => {
+    render(<App />)
+
+    // Wait for loading to finish (hook will set isLoading false after mount)
+    await waitFor(() => {
+      expect(screen.getByTestId('chat-window')).toBeInTheDocument()
+    })
+
+    // Check menu button exists
+    expect(screen.getByTitle(/Open Menu/i)).toBeInTheDocument()
+  })
+
+  it('should open session drawer when menu clicked', async () => {
+    render(<App />)
+
+    await waitFor(() => {
+      expect(screen.getByTestId('chat-window')).toBeInTheDocument()
+    })
+
+    fireEvent.click(screen.getByTitle(/Open Menu/i))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('session-drawer')).toBeInTheDocument()
+    })
+  })
+})