style(backend): ruff format 统一此前批次的排版残留

纯排版无行为变化（ruff format 重排 7 个此前批次的文件），
涉及模块集成回归全绿（67 passed）。

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

backend/app/repositories/customer_repository.py

@@ -29,9 +29,7 @@ def count_business_refs(session: Session, customer_id: int) -> int:
 
     return int(
         session.execute(
-            select(func.count())
-            .select_from(Business)
-            .where(Business.customer_id == customer_id)
+            select(func.count()).select_from(Business).where(Business.customer_id == customer_id)
         ).scalar_one()
     )
 

backend/app/repositories/receipt_repository.py

@@ -88,9 +88,7 @@ def list_receipts(
         is_barter=is_barter,
         settlement_status=settlement_status,
     )
-    return list(
-        session.execute(stmt.order_by(Receipt.id.desc()).offset(offset).limit(limit)).all()
-    )
+    return list(session.execute(stmt.order_by(Receipt.id.desc()).offset(offset).limit(limit)).all())
 
 
 def count_receipts(

backend/app/repositories/shipment_repository.py

@@ -59,9 +59,7 @@ def list_shipments(
 ) -> list[tuple[Shipment, str]]:
     """分页查询发货单（附业务号），按 id 倒序。"""
     stmt = _apply_filters(
-        select(Shipment, Business.business_no).join(
-            Business, Business.id == Shipment.business_id
-        ),
+        select(Shipment, Business.business_no).join(Business, Business.id == Shipment.business_id),
         business_id=business_id,
         ship_date_from=ship_date_from,
         ship_date_to=ship_date_to,