Initial MVP: full-stack music discovery app

Backend (FastAPI):
- User auth with email/password and Spotify OAuth
- Spotify playlist import with audio feature extraction
- AI recommendation engine using Claude API with taste profiling
- Save/bookmark recommendations
- Rate limiting for free tier (10 recs/day, 1 playlist)
- PostgreSQL models with Alembic migrations
- Redis-ready configuration

Frontend (React 19 + TypeScript + Vite + Tailwind):
- Landing page, auth flows (email + Spotify OAuth)
- Dashboard with stats and quick discover
- Playlist management and import from Spotify
- Discover page with custom query support
- Recommendation cards with explanations and save toggle
- Taste profile visualization
- Responsive layout with mobile navigation
- PWA-ready configuration

Infrastructure:
- Docker Compose with PostgreSQL, Redis, backend, frontend
- Environment-based configuration

backend/app/core/config.py

@@ -0,0 +1,35 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    APP_NAME: str = "Vynl"
+    DEBUG: bool = False
+    SECRET_KEY: str = "change-me-in-production"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24 * 7  # 7 days
+
+    # Database
+    DATABASE_URL: str = "postgresql+asyncpg://vynl:vynl@localhost:5432/vynl"
+    DATABASE_URL_SYNC: str = "postgresql://vynl:vynl@localhost:5432/vynl"
+
+    # Redis
+    REDIS_URL: str = "redis://localhost:6379/0"
+
+    # Spotify
+    SPOTIFY_CLIENT_ID: str = ""
+    SPOTIFY_CLIENT_SECRET: str = ""
+    SPOTIFY_REDIRECT_URI: str = "http://localhost:5173/auth/spotify/callback"
+
+    # Claude API
+    ANTHROPIC_API_KEY: str = ""
+
+    # Frontend
+    FRONTEND_URL: str = "http://localhost:5173"
+
+    # Rate limits (free tier)
+    FREE_DAILY_RECOMMENDATIONS: int = 10
+    FREE_MAX_PLAYLISTS: int = 1
+
+    model_config = {"env_file": ".env", "extra": "ignore"}
+
+
+settings = Settings()