Default model choice fails when org policy loads model list after copilot load

Tái hiện vấn đề bằng cách chọn một model khả dụng theo policy qua /config hoặc /settings, sau đó khởi động lại Copilot trong một tổ chức có danh sách model được cấu hình. Theo dõi quá trình phân giải model khi khởi động cùng với việc tải catalog; được xem là hoàn tất khi model mặc định đã cấu hình vẫn được chọn sau khi khởi động, thay vì chỉ xuất hiện trong thời gian ngắn rồi chuyển sang model khác.

Describe the bug

What's happening: ┃
┃
• Your user default is correctly saved ( ~/.copilot/settings.json  →  "model": "GPT-5.6 Sol" ). ┃
• At session startup, the resolver checks GPT-5.6-Sol against the model catalog it has at that instant — only ~150-400ms after auth completes — and doesn't find it ┃
available yet, so it silently falls back to  claude-sonnet-5 . ┃
• This happens before any managed/org policy is even involved (the policy log lines only cover telemetry/bypass permissions, not model allowlists) — so it's not an org ┃
restriction blocking the model. ┃
• The UI briefly shows "Sol" (from your saved default) before the resolver's fallback takes effect and the display corrects to Sonnet — matching exactly what you saw. ┃
┃
This looks like a timing/race condition: the model entitlement/catalog fetch for GPT-5.6-Sol on your account hasn't completed (or propagated) by the time the session binds ┃
its model, so it can't find it in the "available" list yet.

Affected version

No response

Steps to reproduce the behavior

in org with policy-configured model list, slect a policy-avaiable model (not default available model) as default via /config or /settings, then restart copilot, it will show the new model briefly, before defautling back to a differnet model

Expected behavior

expect it to respect the configured default model.

Additional context

No response