- GET /api/notification-channels: requireAuth(), admin sees all rows with owner_email JOIN, non-admin sees global-only
- GET accepts ?owner=global|personal|all filter parameter
- POST /api/notification-channels: requireAdmin(); preserves all four channel_type values (teams/telegram/ntfy/webhook); adds owner_user_id column
- [id] routes: requireAuth() + per-row authorization (isAdmin || isOwner); global rows require admin
- Admin channels page: Owner badge (Global vs Personal: email), Show filter select, disclaimer text for personal channels