[Feature Request] Add API fallback mechanism for auto-mode classifier

Bug Description
Run stopped because the auto mode classifier failed due to a Sonnet 5 1m outage. In the future, it would be great if Claude Code would automatically fall back to e.g. Opus low for the auto classifier in these cases.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.210
• Feedback ID: e878acdb-8359-4f30-840b-36f22dde356f

Errors

Error: claude-sonnet-5[1m] is temporarily unavailable, so auto mode cannot determine the safety of Agent right now. Wait briefly and then try this action again. If it keeps failing, continue with other tasks that don't require this action and come back to it later. Note: reading files, searching code, and other read-only operations do not require the classifier and can still be used.