When OAuth refresh fails during model discovery, getApiKey() now returns
undefined instead of throwing. This allows the app to start and fall back
to other providers, so the user can /login to re-authenticate.
fixes#498
feat(coding-agent): support searching/resuming sessions by ID
- Session picker (pi -r) now searches session IDs in addition to message content
- --session flag accepts UUID prefix (e.g., pi --session a8ec1c2a)
- Documented in README.md
fixes#495
512ae4b4c0