The original regex didn't match the actual error ("No conversation
found with session ID: ..."). Added `no conversation found` pattern.
Removed the inline retry — clearing the session and returning 'error'
lets the existing group-queue.ts backoff loop retry with a fresh
session naturally. Simpler, no duplicate error paths.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>