Fixes two critical issues preventing Traefik proxy startup:
1. TypeError when restarting proxy: Handle null return from get_traefik_versions()
- Add null check before dispatching CheckTraefikVersionForServerJob
- Log warning when version data is unavailable
- Prevents: "Argument #2 must be of type array, null given"
2. Docker network error: Filter out predefined Docker networks
- Add isDockerPredefinedNetwork() helper to centralize network filtering
- Apply filtering in collectDockerNetworksByServer() before operations
- Apply filtering in generateDefaultProxyConfiguration()
- Prevents: "operation is not permitted on predefined default network"
Also: Move $cachedVersionsFile assignment after null check in Proxy.php
Tests: Added 7 new unit tests for network filtering function
All existing tests pass with no regressions
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Add automated Traefik version checking job running weekly on Sundays
- Implement version detection from running containers and comparison with versions.json
- Add notifications across all channels (Email, Discord, Slack, Telegram, Pushover, Webhook) for outdated versions
- Create dismissible callout component with localStorage persistence
- Display cross-branch upgrade warnings (e.g., v3.5 -> v3.6) with changelog links
- Show patch update notifications within same branch
- Add warning icon that appears when callouts are dismissed
- Prevent duplicate notifications during proxy restart by adding restarting parameter
- Fix notification spam with transition-based logic for status changes
- Enable system email settings by default in development mode
- Track last saved/applied proxy settings to detect configuration drift
