fix: 多租户数据隔离P1a+P1b — 工作台/预警/行动计划/因果链按企业过滤

P1a(有entity表查询补齐):
- kpis get/update/delete/restore 跨企业404校验
- kpis create 强制entity=token企业, update禁止改归属
P1b(无entity表join隔离):
- alerts list/resolve join kpi_definitions 按企业过滤
- action_plans list join过滤 + create校验关联KPI归属
- kpi_causality full-network/list join过滤
- dashboard my_dashboard(用户发现) assigned/preset均按企业隔离
测试: 测试KPI种子entity对齐(2→1), pytest 451 passed
实证: 酣客token 6KPI(无博海id) vs 博海token 1KPI(414) 切换隔离正确

backend/tests/test_kpi_causality.py

@@ -17,7 +17,8 @@ BASE = "/api/cma/kpi-causality"
 
 
 def _seed_kpi(db: Session, code: str, name: str = None, dimension: str = "finance",
-              entity_id: int = 2) -> KPIDefinition:
+              entity_id: int = 1) -> KPIDefinition:
+    # entity_id=1 与测试token(账套entity=1)对齐 — 2026-08-23 多租户隔离后必须匹配
     kpi = KPIDefinition(
         kpi_code=code,
         kpi_name=name or code,