fix(business): 唯一键冲突重试改为审计上下文内循环，单条审计无递归

三处 create（业务/发货/回款）的 return _retry_create 是吞异常后正常
退出：外层审计把已回滚的首次尝试记成 success（假成功），重入整个
create_* 违反 audit_service「不支持嵌套」约定，且 _NO_RETRY 死常量
导致持续冲突时无界递归至 RecursionError。改为 audit 内 for 循环
（上限 _NO_RETRY），rollback 后重新锁行与取号，成功/最终失败各恰好
一条审计。新增集成用例锁定两条路径的日志增量。

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

backend/app/services/receipt_service.py

@@ -55,6 +55,9 @@ from app.services.no_generator import next_no
 
 logger = logging.getLogger(__name__)
 
+# 编号唯一键冲突后的重试次数（模式同 business_service._NO_RETRY）
+_NO_RETRY = 1
+
 
 def _to_out(row: tuple) -> ReceiptOut:
     """(receipt, business_no, shipment_no, ship_date) → 响应模型。
@@ -84,9 +87,7 @@ def _to_out(row: tuple) -> ReceiptOut:
 
 def _generate_no(session: Session) -> str:
     """生成回款批次号（HK 前缀；MAX+FOR UPDATE 与 1062 兜底见 no_generator）。"""
-    return next_no(
-        session, model=Receipt, column_name="receipt_batch_no", prefix=NO_PREFIX_RECEIPT
-    )
+    return next_no(session, model=Receipt, column_name="receipt_batch_no", prefix=NO_PREFIX_RECEIPT)
 
 
 def _ensure_shipment_of_business(
@@ -198,59 +199,55 @@ def create_receipt(
         ),
         meta=meta,
     ):
-        if business is None:
-            raise NotFoundError("业务不存在")
-        if business.status != BUSINESS_STATUS_ACTIVE:
-            raise BadRequestError("业务已完成或已终止，禁止新增回款")
-        shipment_no, ship_date = _ensure_shipment_of_business(
-            session, payload.shipment_id, payload.business_id
-        )
-
-        try:
-            receipt = receipt_repository.create(
-                session,
-                Receipt(
-                    receipt_batch_no=batch_no,
-                    business_id=payload.business_id,
-                    shipment_id=payload.shipment_id,
-                    receipt_date=payload.receipt_date,
-                    amount=Decimal(payload.amount),
-                    is_barter=payload.is_barter,
-                    settlement_status=SETTLEMENT_PENDING,
-                    remark=payload.remark,
-                ),
-            )
-            _recalc_totals(session, business)
-            out = _to_out((receipt, business.business_no, shipment_no, ship_date))
-            new_id = receipt.id
-            session.commit()
-        except IntegrityError as exc:
-            session.rollback()
-            if _is_duplicate_entry(exc):
-                # 批次号撞唯一键的残余竞态：兜底重试一次（防无限重试掩盖死锁）
-                return _retry_create(session, payload, operator=operator, meta=meta)
-            raise
+        # 批次号唯一键冲突的重试整体收在审计上下文内（模式同
+        # business_service.create_business）：rollback 释放旧锁，重试前重新
+        # 锁业务行与生成批次号——成功/最终失败各只记一条审计，无递归
+        for attempt in range(_NO_RETRY + 1):
+            try:
+                if business is None:
+                    raise NotFoundError("业务不存在")
+                if business.status != BUSINESS_STATUS_ACTIVE:
+                    raise BadRequestError("业务已完成或已终止，禁止新增回款")
+                shipment_no, ship_date = _ensure_shipment_of_business(
+                    session, payload.shipment_id, payload.business_id
+                )
+                receipt = receipt_repository.create(
+                    session,
+                    Receipt(
+                        receipt_batch_no=batch_no,
+                        business_id=payload.business_id,
+                        shipment_id=payload.shipment_id,
+                        receipt_date=payload.receipt_date,
+                        amount=Decimal(payload.amount),
+                        is_barter=payload.is_barter,
+                        settlement_status=SETTLEMENT_PENDING,
+                        remark=payload.remark,
+                    ),
+                )
+                _recalc_totals(session, business)
+                out = _to_out((receipt, business.business_no, shipment_no, ship_date))
+                new_id, new_no = receipt.id, batch_no  # 固化：commit 后不碰 ORM
+                session.commit()
+                break
+            except IntegrityError as exc:
+                session.rollback()
+                if _is_duplicate_entry(exc) and attempt < _NO_RETRY:
+                    business = business_repository.get_by_id(
+                        session, payload.business_id, for_update=True
+                    )
+                    batch_no = _generate_no(session)
+                    continue
+                raise
 
         logger.info(
             "新增回款 | receipt_id=%s | no=%s | business_id=%s",
             new_id,
-            batch_no,
+            new_no,
             payload.business_id,
         )
         return out
 
 
-def _retry_create(
-    session: Session,
-    payload: ReceiptCreateIn,
-    *,
-    operator,
-    meta: RequestMeta | None,
-) -> ReceiptOut:
-    """批次号撞唯一键后的单次重试（重新锁行与生成编号，防死锁类缺陷掩盖）。"""
-    return create_receipt(session, payload, operator=operator, meta=meta)
-
-
 def update_receipt(
     session: Session,
     receipt_id: int,