feat: login page, 401 interceptor, nav sign-out

frontend/src/App.tsx

@@ -4,6 +4,8 @@ import Dashboard from './pages/Dashboard'
 import MealDetail from './pages/MealDetail'
 import Pantry from './pages/Pantry'
 import ShoppingList from './pages/ShoppingList'
+import Login from './pages/Login'
+import { mealPlannerApi } from './api'
 
 const queryClient = new QueryClient()
 
@@ -26,6 +28,17 @@ function App() {
                     Shopping List
                   </Link>
                 </div>
+                <div className="flex items-center">
+                  <button
+                    onClick={async () => {
+                      await mealPlannerApi.auth.logout().catch(() => {})
+                      window.location.href = '/login'
+                    }}
+                    className="text-sm text-gray-500 hover:text-gray-900"
+                  >
+                    Sign out
+                  </button>
+                </div>
               </div>
             </div>
           </nav>
@@ -35,6 +48,7 @@ function App() {
               <Route path="/meals/:id" element={<MealDetail />} />
               <Route path="/pantry" element={<Pantry />} />
               <Route path="/shopping-list" element={<ShoppingList />} />
+              <Route path="/login" element={<Login />} />
             </Routes>
           </main>
         </div>

frontend/src/api/index.ts

@@ -10,6 +10,16 @@ const api = axios.create({
   withCredentials: true,
 })
 
+api.interceptors.response.use(
+  response => response,
+  error => {
+    if (error.response?.status === 401 && window.location.pathname !== '/login') {
+      window.location.href = '/login'
+    }
+    return Promise.reject(error)
+  }
+)
+
 export const mealPlannerApi = {
   auth: {
     login: (password: string) => api.post('/auth/login', { password }),

frontend/src/pages/Login.tsx

@@ -0,0 +1,54 @@
+import { useState } from 'react'
+import { mealPlannerApi } from '../api'
+
+export default function Login() {
+  const [password, setPassword] = useState('')
+  const [error, setError] = useState('')
+  const [loading, setLoading] = useState(false)
+
+  const handleSubmit = async (e: React.FormEvent) => {
+    e.preventDefault()
+    setError('')
+    setLoading(true)
+    try {
+      await mealPlannerApi.auth.login(password)
+      window.location.href = '/'
+    } catch {
+      setError('Incorrect password. Try again.')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  return (
+    <div className="min-h-screen bg-gray-50 flex items-center justify-center">
+      <div className="bg-white rounded-lg shadow p-8 w-full max-w-sm">
+        <h1 className="text-2xl font-bold text-gray-900 mb-2 text-center">MealPlanner</h1>
+        <p className="text-sm text-gray-500 text-center mb-6">Family login</p>
+        <form onSubmit={handleSubmit} className="space-y-4">
+          <div>
+            <label className="block text-sm font-medium text-gray-700 mb-1">
+              Password
+            </label>
+            <input
+              type="password"
+              value={password}
+              onChange={e => setPassword(e.target.value)}
+              className="w-full border border-gray-300 rounded-lg px-3 py-2 focus:outline-none focus:ring-2 focus:ring-blue-500"
+              autoFocus
+              required
+            />
+          </div>
+          {error && <p className="text-red-600 text-sm">{error}</p>}
+          <button
+            type="submit"
+            disabled={loading}
+            className="w-full bg-blue-600 text-white py-2 rounded-lg hover:bg-blue-700 disabled:opacity-50 font-medium"
+          >
+            {loading ? 'Signing in…' : 'Sign in'}
+          </button>
+        </form>
+      </div>
+    </div>
+  )
+}