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/pages/Dashboard.tsx

@@ -0,0 +1,8 @@
+export default function Dashboard() {
+  return (
+    <div className="space-y-6">
+      <h1 className="text-2xl font-bold text-gray-900">This Week's Meal Plan</h1>
+      <p className="text-gray-500">Meal planning UI coming soon...</p>
+    </div>
+  )
+}

frontend/src/pages/MealDetail.tsx

@@ -0,0 +1,11 @@
+import { useParams } from 'react-router-dom'
+
+export default function MealDetail() {
+  const { id } = useParams()
+  return (
+    <div className="space-y-6">
+      <h1 className="text-2xl font-bold text-gray-900">Meal Detail</h1>
+      <p className="text-gray-500">Meal {id} details coming soon...</p>
+    </div>
+  )
+}