fix(T+): 补齐指导成本与读取服务保护

补充业务详情指导成本入口、来源版本和历史封存保护，接入月份锁并完善权限复核。
同步接入读取服务运行状态到页面，补充前端控制、回归测试和服务端只读连接授权校验。

定向隔离测试：89 项通过，1 条既有 Starlette 弃用警告。

backend/app/api/v1/business/businesses.py

@@ -25,6 +25,7 @@ from app.schemas.business import (
     OwnershipChangeLogOut,
 )
 from app.schemas.business_source import (
+    GuidanceConfirmIn,
     SalesRelationConfirmIn,
     SalesRelationQuery,
     SalesRelationReleaseIn,
@@ -72,6 +73,17 @@ def confirm_source_price(session: DbSession, actor: PayrollWriter, business_id:
     return ok(business_source.confirm_missing_source_price(session, business_id, document_id, payload, actor, meta))
 
 
+@router.put("/{business_id}/guidance")
+def confirm_guidance(session: DbSession, actor: PayrollWriter, business_id: Annotated[int, Path(ge=1)],
+                     payload: GuidanceConfirmIn, meta: RequestMetaDep):
+    """从本地发货明细登记来源产品的发货月份指导成本。"""
+    from app.services.authorization_service import require_permission
+
+    require_permission(session, actor, "payroll:prepare")
+    require_permission(session, actor, "tplus:facts")
+    return ok(business_source.confirm_guidance(session, business_id, payload, actor, meta))
+
+
 @router.get("/{business_id}/sales-relation-candidates")
 def sales_relation_candidates(session: DbSession, _: CurrentUser, business_id: Annotated[int, Path(ge=1)],
                               query: Annotated[SalesRelationQuery, Query()]):