test(proxy): assert the admin substitution through behavior, not through a mock

The guard cell mocked common_checks and read user_object out of its call
kwargs, so it pinned the shape of an internal call rather than anything a
caller can see. It now drives an admin-only route with a non-admin DB row,
asserts the call is allowed, and asserts the same route rejects the same row
when the token is not admin, which is the observable consequence of forcing
the role.

That removes the TQ008 suppression the previous commit added. Docstrings cut
to one line each. scripts/test_quality_gate.py --base c8114ba41f is clean.

tests/test_litellm/proxy/auth/test_user_api_key_auth.py

@@ -4252,8 +4252,7 @@ async def test_centralized_checks_skip_end_user_lookup_without_a_token_budget():
 
 
 def _proxy_admin_world(user_row: LiteLLM_UserTable):
-    """The proxy globals the centralized gate reads, with ``user_row`` already in the
-    user cache so get_user_object resolves it without a DB round trip."""
+    """Same shape as _proxy_attrs_for_centralized_checks, with user_row in the cache."""
     import litellm.proxy.proxy_server as _proxy_server_mod
     from litellm.proxy.common_utils.user_api_key_cache import UserApiKeyCache
     from litellm.proxy.utils import ProxyLogging
@@ -4284,14 +4283,7 @@ def _proxy_admin_world(user_row: LiteLLM_UserTable):
 
 @pytest.mark.asyncio
 async def test_centralized_checks_enforce_personal_budget_for_proxy_admin_token():
-    """GH#41226: a proxy admin stays subject to their own personal budget.
-
-    common_checks reads the admin role off user_object rather than off the token, so the
-    gate substitutes an admin user_object whenever the token says PROXY_ADMIN. Rebuilding
-    that object from scratch dropped max_budget, and the personal-budget check returns
-    early on a None budget, so an admin holding an external JWT kept getting completions
-    after their personal budget was spent.
-    """
+    """GH#41226: a proxy admin stays subject to their own personal budget."""
     admin_row = LiteLLM_UserTable(
         user_id="admin-user",
         user_role=LitellmUserRoles.PROXY_ADMIN.value,
@@ -4314,11 +4306,18 @@ async def test_centralized_checks_enforce_personal_budget_for_proxy_admin_token(
 
 
 @pytest.mark.asyncio
-async def test_centralized_checks_keep_admin_role_when_the_db_row_is_not_admin():
-    """The other half of GH#41226: forcing the budget back must not stop the token from
-    forcing the admin role. A JWT or master-key admin whose DB row carries a non-admin
-    user_role still has to reach common_checks as PROXY_ADMIN, or admin-only routes would
-    start rejecting them."""
+def _route_request(route: str):
+    from fastapi import Request
+    from starlette.datastructures import URL
+
+    request = Request(scope={"type": "http"})
+    request._url = URL(url=route)
+    return request
+
+
+@pytest.mark.asyncio
+async def test_centralized_checks_keep_admin_route_access_when_the_db_row_is_not_admin():
+    """GH#41226: an admin token still reaches an admin-only route when its row is not admin."""
     demoted_row = LiteLLM_UserTable(
         user_id="admin-user",
         user_role=LitellmUserRoles.INTERNAL_USER.value,
@@ -4328,20 +4327,25 @@ async def test_centralized_checks_keep_admin_role_when_the_db_row_is_not_admin()
     token = UserAPIKeyAuth(user_id="admin-user", user_role=LitellmUserRoles.PROXY_ADMIN)
 
     with _proxy_admin_world(demoted_row):
-        with patch(  # test-quality-ok: what the substitution hands common_checks IS the subject; no HTTP boundary and no injection seam on that call
-            "litellm.proxy.auth.user_api_key_auth.common_checks",
-            new_callable=AsyncMock,
-        ) as mock_checks:
+        await _run_centralized_common_checks(
+            user_api_key_auth_obj=token,
+            request=_route_request("/user/new"),
+            request_data={},
+            route="/user/new",
+        )
+
+        non_admin_token = UserAPIKeyAuth(
+            user_id="admin-user", user_role=LitellmUserRoles.INTERNAL_USER
+        )
+        with pytest.raises(Exception, match="Only proxy admin can be used") as exc_info:
             await _run_centralized_common_checks(
-                user_api_key_auth_obj=token,
-                request=_chat_request(),
-                request_data={"model": "gpt-4o-mini", "messages": [{"role": "user", "content": "hi"}]},
-                route="/chat/completions",
+                user_api_key_auth_obj=non_admin_token,
+                request=_route_request("/user/new"),
+                request_data={},
+                route="/user/new",
             )
 
-    seen_user_object = mock_checks.await_args.kwargs["user_object"]
-    assert seen_user_object.user_role == LitellmUserRoles.PROXY_ADMIN
-    assert seen_user_object.max_budget == 500.0
+    assert "internal_user" in str(exc_info.value)
 
 
 @pytest.mark.asyncio