feat: add Phase 1 infrastructure skeleton

Backend (FastAPI):
- docker-compose with all 4 services
- FastAPI app with health endpoints
- SQLAlchemy models for all tables
- Placeholder API endpoints for all routes
- Config and database modules
- requirements.txt with all dependencies

Frontend (React):
- package.json with React, Tailwind, React Query, React Router
- Vite config with API proxy
- Tailwind and TypeScript configs
- Basic App with routing skeleton
- Placeholder pages (Dashboard, MealDetail, Pantry)

Infrastructure:
- nginx config for reverse proxy
- Dockerfile for backend and frontend

frontend/src/App.tsx

@@ -0,0 +1,41 @@
+import { BrowserRouter, Routes, Route, Link } from 'react-router-dom'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import Dashboard from './pages/Dashboard'
+import MealDetail from './pages/MealDetail'
+import Pantry from './pages/Pantry'
+
+const queryClient = new QueryClient()
+
+function App() {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <BrowserRouter>
+        <div className="min-h-screen bg-gray-50">
+          <nav className="bg-white shadow-sm">
+            <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
+              <div className="flex justify-between h-16">
+                <div className="flex space-x-8">
+                  <Link to="/" className="inline-flex items-center px-1 pt-1 text-sm font-medium text-gray-900">
+                    MealPlanner
+                  </Link>
+                  <Link to="/pantry" className="inline-flex items-center px-1 pt-1 text-sm font-medium text-gray-500 hover:text-gray-900">
+                    Pantry
+                  </Link>
+                </div>
+              </div>
+            </div>
+          </nav>
+          <main className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
+            <Routes>
+              <Route path="/" element={<Dashboard />} />
+              <Route path="/meals/:id" element={<MealDetail />} />
+              <Route path="/pantry" element={<Pantry />} />
+            </Routes>
+          </main>
+        </div>
+      </BrowserRouter>
+    </QueryClientProvider>
+  )
+}
+
+export default App