Merges FN-4015 to add stale module-resolution incident detection and self-healing in the engine (`transient-error-detector.ts`, `self-healing.ts`) with mobile regression coverage for the shared `AgentErrorDetailsModal` layout.
Fusion-Task-Id: FN-4015
pi-ai's openai-codex-responses provider surfaces ChatGPT-plan WebSocket
drops as bare "WebSocket error" / "WebSocket closed <code>". The
underlying ErrorEvent.error is dropped by extractWebSocketError (it only
inspects event.message), so the cause is gone by the time we see it.
The engine then propagated these as fatal failures instead of retrying
a transient network blip.
- Add WebSocket patterns to TRANSIENT_ERROR_PATTERNS so the executor's
existing transient retry path picks them up.
- Tag the model id onto the thrown error and emit a structured warn in
promptSessionAndCheck so future drops can be triaged by transport.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
