Added Mattermost webhook notifications for infrastructure services:
- **Netdata**: Health monitoring alerts sent to Mattermost
- Configured via MATTERMOST_WEBHOOK_URL environment variable
- All alert roles route to Mattermost notifications channel
- **Restic/Backrest**: Backup status notifications
- Webhook URL passed as environment variable
- Backrest web UI can be configured to use the webhook
- **Watchtower**: Container update notifications
- Uses Shoutrrr mattermost:// URL format
- Sends notifications when containers are updated
Configuration:
- Webhook URL stored securely in .env file
- All services reference ${MATTERMOST_WEBHOOK_URL} variable
- Watchtower uses specialized Shoutrrr format URL
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
Sebastian Krüger
151fdc4b00