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/auth.py

@@ -4,7 +4,7 @@ from fastapi import APIRouter, Depends, HTTPException, Request
 from sqlalchemy.orm import Session
 from app.database import get_db
 from app.models import User, UserEntity, Entity, OperationLog
-from app.auth_middleware import create_token, require_auth, ROLES
+from app.auth_middleware import create_token, require_auth, require_auth_401, ROLES
 
 router = APIRouter(prefix="/api/cma/auth", tags=["认证"])
 
@@ -111,8 +111,13 @@ def get_me(request: Request, current_user: User = Depends(require_auth), db: Ses
 
 
 @router.get("/roles")
-def list_roles():
-    """返回角色列表（给前端用）"""
+def list_roles(_=Depends(require_auth_401)):
+    """返回角色列表（给前端用）
+
+    2026-09-14 安全修复（cma-api-auth-surface-audit-20260914）：原无鉴权公开返回角色
+    枚举（对外暴露系统角色模型 + 便于针对性撞库）。仓内检索确认无任何前端/脚本调用方
+    （前端用 /permissions/modules 的 roles 字段），故直接补 require_auth_401。
+    """
     return {
         "data": [
             {"code": k, "name": v["name"], "priority": v["priority"]}