#26424 auth_exception_handler logs 401/403 permission denials at ERROR level with full traceback (should be WARNING)
## Bug Description
When a user attempts to call a model they don't have permission to access, LiteLLM logs the event at **ERROR** level with a full traceback in `auth_exception_handler.py`. This is noisy and misleading — a permission denial is expected behavior, not a service error.
## Steps to Reproduce
1. Create a user with restricted `models` (e.g. `['common-models']`) 2. Call a model outside their allowed group (e.g. `claude-opus-4-7` when only `common-models` is permitted) 3. Observe logs
## Current Behavior
``` 20:24:13 - LiteLLM Proxy:ERROR: auth_exception_handler.py:78 - litellm.proxy.proxy_server.user_api_key_auth(): Exception occured - Requester IP Address:172.18.0.2 Traceback (most recent call last): File ".../user_api_key_auth.py", line 1508, in _user_api_key_auth_builder _ = await common_checks(...) File ".../auth_checks.py", line 494, in common_checks await can_user_call_model(...) File ".../auth_checks.py", line 2877, in can_user_call_model return _can_object_call_model(...) File ".../auth_checks.py", line 2706, in _can_object_call_model raise ProxyException(...) litellm.proxy._types.ProxyException INFO: "POST /chat/completions HTTP/1.1"…