When a user adds a custom endpoint via 'hermes model' → 'Custom
endpoint', it now automatically saves to custom_providers in
config.yaml so it persists and appears in the provider menu on
subsequent runs. Deduplicates by base_url.
Auto-generated names based on URL:
http://localhost:8000/v1 → 'Local (localhost:8000)'
https://xyz.runpod.ai/v1 → 'RunPod (xyz.runpod.ai)'
https://api.example.com/v1 → 'Api.example.com'
Also adds 'Remove a saved custom provider' option to the menu
(only shown when custom providers exist) with a selection UI
to pick which one to remove.
Users can also manually edit custom_providers in config.yaml
for full control over names and settings.