feat:新增接口

schemas/purchase.py

@@ -14,11 +14,17 @@ class PurchaseReq(BaseModel):
 
 
 class PurchaseResp(BaseModel):
-    """申购结果：最新余额 + 该产品最新持仓。"""
+    """申购结果：order_no + status（已确认 / 风控挂起）。
 
-    balance: Decimal
-    holding: HoldingResp
+    已确认时返回最新余额 + 该产品持仓；风控挂起时账户/持仓不变，仅返回预警关联。
+    """
+
+    order_no: str
+    status: str
+    balance: Decimal | None = None
+    holding: HoldingResp | None = None
+    alert_id: int | None = None
 
     @field_serializer("balance")
-    def _fmt_balance(self, value: Decimal) -> str:
-        return f"{value:.2f}"
+    def _fmt_balance(self, value: Decimal | None) -> str | None:
+        return f"{value:.2f}" if value is not None else None