[Question / Potential bug] Inconsistent models listing with Microsoft Agent Framework (.NET) + Copilot SDK

Hi,

I've added an integration with Microsoft Agent Framework (.NET) inside a WinForms application and I've experienced inconsistent listing of CopilotClient models using the ```ListModelsAsync``` function.

### Context
I'm using a GH user that was invited to a GH organization which got assigned a Copilot seat. I have a suspicion that the models (1 model only: gpt-4.1) returned are from my regular GH user which has no Copilot seat/license assigned to it.

### OS
Windows

### NuGet Packages

- Microsoft.Agents.AI (1.0.0)
- Microsoft.Agents.AI.GitHub.Copilot (1.0.0-preview.260402.1)
- GitHub.Copilot.SDK (0.2.1)

### How I achieve getting wrong list of models

1. Start and complete the Auth Device Flow with GH using the GH Copilot public client ID to obtain a GH token
2. Store the valid GH token
3. Create a ```CopilotClient``` with ```CopilotClientOptions``` (GithubToken, ```UseLoggedInUser = false```) and start it.
4. Obtain the list of models by calling ```await client.ListModelsAsync()```
5. Only ```gpt-4.1``` is returned, expected the same models available through VS Code.

### Questions
- Am I using the correct auth flow to get the proper GH token which has access to the Copilot seat assigned from my organization?
- Is there ways to call an HTTP endpoint in order to get the list of models instead of instanciating a CopilotClient. I have seen that VS Code codebase calls ```https://api.github.com/copilot_internal/*``` endpoints which I've read would be against ToS to call.

### Maybe a bug maybe not...
A colleague found an interesting route that could maybe explain the 1 model returned. When the CLI gets launched with ```--no-auto-update``` it picks up an old version in his ```C:/users/[username]/.copilot\pkg\win32-x64\0.0.403```. When the parameter ```--no-auto-update``` isn't there it picks up this version ```C:\Users\[username]\.copilot\pkg\universal\1.0.14```. He tested it manually by launching the CLI from the bundled ```copilot.exe``` inside our WinForm app with PowerShell and he was able to reproduce the same error which resulted in only getting 1 model (gpt-4.1) returned.

Start with the CopilotClientOptions setup, the Auth Device Flow, and the ListModelsAsync call described in the issue. Reproduce the result with the listed NuGet packages and compare the CLI builds 0.0.403 and 1.0.14. Done means determining whether the token or CLI version explains the model-list difference and documenting the expected behavior.

Written by the indexing model from the issue text.