## What changed
- Emit turn-scoped authentication recovery started and completed events when a model provider refreshes expired credentials.
- Add stable `modelProvider/authRecoveryStarted` and `modelProvider/authRecoveryCompleted` app-server notifications with the thread, turn, provider, and user-facing message.
- Show recovery progress in the TUI and `codex exec`, including Amazon Bedrock session reauthentication.
## Testing
- Cover provider recovery success and failure events, app-server routing, client rendering, and Amazon Bedrock credential refresh.
GitOrigin-RevId: 3010c38d0676f18bced27761cf86dd38344d09f9
