Newly enabled model remains unavailable until local Copilot state/cache/login is cleared

Describe the bug

Newly enabled Copilot models can remain unavailable because the local model catalog does not refresh. Sonnet 5 was enabled in GitHub settings but unavailable in CLI and Visual Studio until local Copilot state/cache was manually reset. This seems to also affect the model list in the Visual Studio copilot extension. It was never a problem with Visual studio before I installed CLI and wasn't an issue for my coworkers who haven't used the CLI.

Note: I did both renames and re-login in the repro, I didn't check the model list in-between, so I'm unclear on what specifically fixed it and I don't have the admin rights to keep testing this by enabling models.

Affected version

1.0.80, also affected Visual Studio Insiders 12106.202

Steps to reproduce the behavior

1. Enable a previously unavailable model in Copilot settings.
2. Restart/re-authenticate CLI and Visual Studio.
3. Model remains unavailable.
4. Close Copilot and VS
5. Rename %LOCALAPPDATA%\copilot to something like copilot-backup.
6. Rename %USERPROFILE%.copilot\config.json to config.json.backup.
7. Start Copilot CLO, /logout /login
8. Model becomes available in CLI and Visual Studio.

Expected behavior

I assume model availability should refresh on restart at least. I don't see any documentation for manually updating the model list, so I assume it isn't something the user is supposed to worry about.

Additional context

No response

Start by reproducing the model availability flow in the CLI and Visual Studio after enabling a model, using the reported %LOCALAPPDATA%\copilot and %USERPROFILE%.copilot\config.json state locations and /logout /login commands. Compare behavior before and after manually renaming those files; done means the model catalog refreshes after restart or re-authentication without manual state removal.