Claude Opus 4.6 (high) returns "model not supported" error after being told to wait for quota reset on GitHub Copilot Pro+

**Description**
After being prompted by the CLI to wait until a specific time before using Claude Opus 4.6 (high)
due to quota limits, I waited as instructed. Upon retrying, I now receive the following error:

Execution failed: CAPIError: 400 The requested model is not supported.
(Request ID: 49DD:6BE68:13F49D2:16EC696:69E6DD3C)

**Actual Behavior**
Error: CAPIError: 400 The requested model is not supported

**Environment**
- Plan: GitHub Copilot Pro+
- CLI Version: GitHub Copilot CLI 1.0.32
- OS: Windows

**Notes**
The error message is misleading -- it says "model not supported" rather than a quota or
availability issue, making it hard to diagnose.

### Affected version

GitHub Copilot CLI 1.0.32 onwards

### Steps to reproduce the behavior

**Steps to Reproduce**
1. Select Claude Opus 4.6 (high) via `/model` in Copilot CLI
2. Hit quota limit -- CLI prompts to wait until a specific time
3. Wait until the indicated time has passed
4. Try again -- error occurs

### Expected behavior

**Expected Behavior**
The model should be accessible after the quota reset window.

### Additional context

_No response_

Comienza con el flujo de `/model` en GitHub Copilot CLI 1.0.32 y reproduce el fallo después del reinicio de cuota indicado en Windows. Rastrea la solicitud para Claude Opus 4.6 (high) y compara la respuesta reportada con el estado de cuota o disponibilidad. Se considera terminado cuando el modelo funciona después del reinicio o el error identifica claramente la limitación real.

Escrito por el modelo de indexación a partir del texto del issue.