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

backend/app/config.py

@@ -0,0 +1,23 @@
+from pydantic_settings import BaseSettings
+from typing import Optional
+
+
+class Settings(BaseSettings):
+    DATABASE_URL: str
+    SENDGRID_API_KEY: Optional[str] = None
+    LUCKY_CA_URL: str = "https://www.luckyncal.com"
+    AI_IMAGE_ENABLED: bool = False
+    AI_IMAGE_PROVIDER: Optional[str] = None
+    AI_IMAGE_API_KEY: Optional[str] = None
+    LOG_LEVEL: str = "INFO"
+    SECRET_KEY: str = "dev-secret-key"
+
+    FAMILY_EMAIL_1: Optional[str] = None
+    FAMILY_EMAIL_2: Optional[str] = None
+    RECIPES_EMAIL: Optional[str] = None
+
+    class Config:
+        env_file = ".env"
+
+
+settings = Settings()