- Rewrite NotificationToaster with max-ID watermark for reliable
new-notification detection and faster unread count polling (15s)
- Block connection search and requests when sender has
accept_connections disabled (backend + frontend gate)
- Remove duplicate sender_settings fetch in send_connection_request
- Show actionable error messages in toast respond failures
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>