fix(security): retire check-governance + scope /reports/dupont to session entity

- data_quality.py: remove GET /check-governance (no caller repo-wide; its
  entity_id param had no session auth -> cross-tenant read; duplicate of
  governance-check) -> the path now returns 404
- reports.py: /reports/dupont resolves the analysis target from the session
  account (assert_entity_slug_scope / resolve_session_slug); explicit
  cross-entity entity param -> 403, illegal value -> 400; the 2026-08-31
  cross-entity exemption is revoked (docstring updated)
- frontend: drop the checkGovernance api definition; DupontAnalysis.vue
  entity radio group -> read-only session entity tag, request without param
- tests: TestCheckGovernanceRetired (404 x2), TestDupontSessionScope (3),
  TestDupont reworked to account-bound tokens (8 tests)
- docs/api-verification-split.md: drop the retired row, note 334/404 -> 333/403

pytest: 10 failed / 957 passed / 1 xfailed vs HEAD baseline 10 failed /
951 passed / 1 xfailed (identical failure set -> zero regression)

(cma-residual-cross-entity-cleanup-20260914)

frontend/src/api/index.ts

@@ -362,9 +362,9 @@ export const dataQualityApi = {
   logs: (params?: any) => api.get('/data-quality/logs', { params }),
   updateLog: (id: number, data: any) => api.put(`/data-quality/logs/${id}`, data),
   deleteLog: (id: number) => api.delete(`/data-quality/logs/${id}`),
-  // DAMA数据治理规则检查（财务七规则）
-  checkGovernance: (params?: any) => api.get('/data-quality/check-governance', { params }),
-  // 财务七规则检查（最终方案：评分+7规则+实体筛选，只读幂等）
+  // DAMA数据治理规则检查（财务七规则）— /check-governance 已于 2026-09-14 下线
+  //   （cma-residual-cross-entity-cleanup-20260914：无调用方 + entity_id 参数无会话鉴权跨租户）
+  // 财务七规则检查（唯一入口：评分+7规则+实体筛选，只读幂等；实体按会话账套）
   governanceCheck: (params?: any) => api.get('/data-quality/governance-check', { params }),
 }