Service account can now impersonate a Workspace user (set gcal_impersonate_email in config) to unlock attendee invitations with push notifications. Falls back to silent event creation if impersonation is not configured. Setup required in Google Admin Console: Security → API Controls → Domain-wide delegation → Add service account client_id with scope: https://www.googleapis.com/auth/calendar Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>