品种增加每点价值字段，PNL计算支持不同品种差异化配置

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

ft-app/app/routers/admin.py

@@ -48,6 +48,7 @@ def admin_page(request: Request, db: Session = Depends(get_db)):
             "code": p.code,
             "name": p.name,
             "exchange": p.exchange,
+            "point_value": p.point_value,
             "contracts": contract_list,
         })
 
@@ -71,11 +72,12 @@ def create_product(
     code: str = Form(...),
     name: str = Form(...),
     exchange: str = Form(...),
+    point_value: int = Form(20),
     db: Session = Depends(get_db),
 ):
     existing = db.query(Product).filter(Product.code == code.upper()).first()
     if not existing:
-        p = Product(code=code.upper(), name=name, exchange=exchange)
+        p = Product(code=code.upper(), name=name, exchange=exchange, point_value=point_value)
         db.add(p)
         db.commit()
     return RedirectResponse("/admin/?tab=product", status_code=303)