fix(security): close unauthenticated CMA user API surface + audit tool (cma-api-auth-surface-audit-20260914)

Root cause: main.py include_router had no global auth dependency; user routers
(products/cost/predict/...) relied on assert_entity_scope, which treats a
missing session token as the Bot service channel and lets the request through.
Result: 46 user endpoints returned data without any token on a public site.

Changes:
- auth_middleware.py: add require_auth_401 (missing Bearer -> 401, delegates to
  require_auth otherwise); 401/403 semantics are explicit.
- router-level Depends(require_auth_401) on products, cost, predict,
  notifications, permissions, tenant, alignment; endpoint-level on
  /auth/roles and /admin/cache/clear.
- deps.py: document that get_entity_id/assert_entity_scope are NOT auth.
- frontend: add the missing Bearer header to 5 tokenless fetch/axios calls that
  hit the newly protected endpoints (KPIAlignment x2, RolePermissions x2,
  Dashboard x1).
- tests: new test_api_auth_surface_20260914.py (58 cases: no-token 401,
  token 200, cross-entity 403, bot channel unchanged); adapt test_predict /
  test_kpi_forecast to send session tokens like production.
- scripts/audit_api_auth_surface.py: reusable FastAPI dependency-graph audit
  (423 endpoints; A bot / B gap / C public), exits 1 when a B-class gap exists.

backend/app/api/alignment.py

@@ -9,11 +9,14 @@ from datetime import datetime
 import json
 
 from app.database import get_db
-from app.auth_middleware import require_auth, require_role
+from app.auth_middleware import require_auth, require_role, require_auth_401
 from app.models import KPIDefinition, OperationLog, RolePermission
 
 router = APIRouter(prefix="/api/cma/alignment", tags=["KPI目标对齐"],
-    # 不设全局权限，每个接口单独控制
+    # 用户端点：router 级要求会话 Bearer 鉴权（cma-api-auth-surface-audit-20260914）；
+    # 原注释「不设全局权限，每个接口单独控制」保留语义——写接口仍各自叠加 require_role，
+    # router 级只是「至少已认证」底线（补齐 /modes、GET /config 原无鉴权的缺口）。
+    dependencies=[Depends(require_auth_401)],
 )
 
 # 三种对齐模式定义