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/app/main.py

@@ -0,0 +1,65 @@
+"""FastAPI application entry point"""
+import os
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.core.config import settings
+from app.routes import cards, auth, sync
+from app.mcp_server import AICardMcpServer
+
+# Initialize MCP server
+enable_mcp = os.getenv("ENABLE_MCP", "true").lower() == "true"
+mcp_server = AICardMcpServer(enable_mcp=enable_mcp)
+
+# Get FastAPI app from MCP server
+app = mcp_server.get_app()
+
+# Update app configuration
+app.title = settings.app_name
+app.version = settings.app_version
+app.docs_url = "/docs"
+app.redoc_url = "/redoc"
+
+# CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.cors_origins,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(auth.router, prefix=settings.api_v1_prefix)
+app.include_router(cards.router, prefix=settings.api_v1_prefix)
+app.include_router(sync.router, prefix=settings.api_v1_prefix)
+
+
+@app.get("/")
+async def root():
+    """Root endpoint"""
+    return {
+        "app": settings.app_name,
+        "version": settings.app_version,
+        "status": "running"
+    }
+
+
+@app.get("/health")
+async def health_check():
+    """Health check endpoint"""
+    return {
+        "status": "healthy",
+        "mcp_enabled": enable_mcp,
+        "mcp_endpoint": "/mcp" if enable_mcp else None
+    }
+
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(
+        "app.main:app",
+        host="0.0.0.0",
+        port=8000,
+        reload=True
+    )