Add complete ai.card Rust implementation

- Implement complete Rust API server with axum framework
- Add database abstraction supporting PostgreSQL and SQLite
- Implement comprehensive gacha system with probability calculations
- Add JWT authentication with atproto DID integration
- Create card master data system with rarities (Normal, Rare, SuperRare, Kira, Unique)
- Implement draw history tracking and collection management
- Add API endpoints for authentication, card drawing, and collection viewing
- Include database migrations for both PostgreSQL and SQLite
- Maintain full compatibility with Python API implementation
- Add comprehensive documentation and development guide

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

python/api/requirements.txt

@@ -0,0 +1,20 @@
+fastapi>=0.104.1
+uvicorn[standard]>=0.24.0
+pydantic>=2.7.0,<3.0.0
+pydantic-settings>=2.1.0
+python-multipart==0.0.6
+httpx>=0.25.0,<0.29.0
+python-jose[cryptography]==3.3.0
+passlib[bcrypt]==1.7.4
+sqlalchemy>=2.0.23
+greenlet>=3.0.0
+alembic>=1.12.1
+# asyncpg==0.29.0  # Disabled: requires compilation
+# psycopg2-binary==2.9.9  # Disabled: requires compilation
+aiosqlite>=0.19.0
+python-dotenv==1.0.0
+pytest==7.4.3
+pytest-asyncio==0.21.1
+atproto>=0.0.55
+# supabase>=2.3.0  # Temporarily disabled due to httpx version conflict
+fastapi-mcp==0.1.0