新增交易记录功能，支持开平仓和盈亏计算

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ft-app/app/main.py

@@ -7,7 +7,7 @@ from starlette.middleware.base import BaseHTTPMiddleware
 from app.database import engine, Base, SessionLocal
 from app.models import User
 from app.seed import seed
-from app.routers import contracts, admin, auth, positions
+from app.routers import contracts, admin, auth, positions, trades
 
 TEMPLATES_DIR = Path(__file__).parent / "templates"
 
@@ -57,6 +57,7 @@ app.include_router(auth.router)
 app.include_router(contracts.router)
 app.include_router(admin.router)
 app.include_router(positions.router)
+app.include_router(trades.router)
 
 
 @app.get("/")