In list_authenticated_providers(), providers like qwen-oauth that use
OAuth authentication were incorrectly flagged as authenticated because
the env-var check fell back to models.dev provider env vars (e.g.
DASHSCOPE_API_KEY for alibaba). Any user with an alibaba API key would
see a ghost qwen-oauth entry in /model picker with 0 models listed.
Fix: skip providers whose auth_type is not api_key in the env-var
detection section (step 1). OAuth/external-process providers are
properly handled in step 2 (HERMES_OVERLAYS) which checks the auth store.
5eefdd9c02