@

支付提交增加 Tx 预校验：提交前链上验签收款地址与金额，防止转错地址；409 错误展示友好中文提示并自动对账恢复

- 新增 validate_intent_tx 方法及 POST /api/payments/intents/{id}/validate 端点，
  在提交前查链上 receipt 对比收款地址和金额，mismatch 直接拦截
- 新增 handleSubmit409 辅助函数，根据后端错误详情分流处理：
  已支付→自动 reconcile，已过期→提示重下单，其他→透传具体原因
- submit/validate 路由透传后端 detail 字段，生产环境也能看到具体错误
- 手动转账面板粘贴 tx hash 后自动触发验证，绿色/红色提示，
  验证不通过时禁用提交按钮

Tested: tsc --noEmit + ruff check . 均通过
@

web/services/payment_api.py

@@ -11,6 +11,7 @@ from web.core import (
     ConfirmPaymentTxRequest,
     CreatePaymentIntentRequest,
     SubmitPaymentTxRequest,
+    ValidatePaymentTxRequest,
     WalletChallengeRequest,
     WalletUnbindRequest,
     WalletVerifyRequest,
@@ -155,6 +156,22 @@ def submit_payment_tx(
         _raise_payment_error(exc)
 
 
+def validate_payment_tx(
+    request: Request,
+    intent_id: str,
+    body: ValidatePaymentTxRequest,
+) -> Dict[str, Any]:
+    identity = _require_payment_identity(request)
+    try:
+        return legacy_routes.PAYMENT_CHECKOUT.validate_intent_tx(
+            user_id=identity["user_id"],
+            intent_id=intent_id,
+            tx_hash=body.tx_hash,
+        )
+    except legacy_routes.PaymentCheckoutError as exc:
+        _raise_payment_error(exc)
+
+
 def confirm_payment_tx(
     request: Request,
     intent_id: str,