feat(T+): 完成数据贯通与自动接入闭环

打通 T+ 快照、业务、发货、回款和核算准备链路，保留来源差异并提供待补状态。
新增业务自动接入任务、跨平台读取服务托管、权限复核、来源关联和前端核对页面。
补充迁移、隔离集成测试、浏览器模拟验收及角色授权边界修复。

backend/app/services/payroll_inputs.py

@@ -37,6 +37,11 @@ def detail(session, business_id):
 
 
 def setup(session, business_id, payload, operator, meta=None):
+    source_business = session.get(Business, business_id)
+    if source_business and source_business.integration_json:
+        from app.services.business_source import prepare
+
+        return prepare(session, business_id, payload, operator, meta)
     with audit_service.audit(
         session,
         operator=operator,
@@ -121,15 +126,21 @@ def setup(session, business_id, payload, operator, meta=None):
                 }
             )
         receipts = list(session.scalars(select(Receipt).where(Receipt.business_id == business_id)))
-        if any(r.is_barter for r in receipts):
-            raise BadRequestError("抵顶特殊绩效继续线下处理，不进入普通FIFO核算")
+        # 用户 2026-11-03：抵顶按普通业务计算，特殊应得绩效线下核实，
+        # 不自动乘80%，也不因抵顶标记阻断整个客户的正常平账。
         if current:
             previous_costs = {s["line_id"]: s for s in current.data_json["shipments"]}
             for ship in ships:
                 old = previous_costs.get(ship["line_id"])
-                if old and (old["cost_total"] != ship["cost_total"] or old["date"] != ship["date"]):
-                    raise BadRequestError("原发货月份指导成本已封存，不得随后续回款更改")
-        handovers = [h.model_dump(mode="json") for h in payload.handovers]
+                if old:
+                    old_unit_cost = old.get("unit_cost")
+                    if (old["cost_total"] != ship["cost_total"] or old["date"] != ship["date"]
+                            or old_unit_cost is None or Decimal(str(old_unit_cost)) != Decimal(ship["unit_cost"])):
+                        raise BadRequestError("原发货月份指导成本已封存，不得随后续回款更改")
+        if current and "handovers" not in payload.model_fields_set:
+            handovers = current.data_json.get("facts", {}).get("handovers", [])
+        else:
+            handovers = [h.model_dump(mode="json") for h in payload.handovers]
         if any(h["business_key"] != key for h in handovers):
             raise BadRequestError("交接记录不属于本业务")
         values = {