- Register ISettingsModalService, INotificationService, IUpdateCheckService via assembly scanning (marker interfaces)
- Add IApplicationOptionsValidator<TOptions> marker; scan only those for IValidateOptions registration
- Fix ApplicationLifecycleLoggingHostedService: log RestartCommand/ReloadCommand/StatusCommand (no ApplyCommand)
- NavMenu: spin animation for update-check button icon when checking; single icon with conditional nav-footer-spin class
- Add NotificationHost/NotificationToast components and NotificationService for toasts
- Effective config save flow, restore result, save service; various EffectiveConfig and DnsmasqOptions/validator updates
- Test and script updates; docker-compose.test.yml, appsettings, DnsmasqConfKeys/tooltips/sections