Resolved conflicts:
- Calculator.csproj: Keep Mages 3.0.1 (from dev) + Avalonia packages
- Explorer SettingsViewModel.cs: Use PromptUserSelectFileAsync for ShellPath
- ExplorerSettings.xaml: Removed (deleted in HEAD)
- packages.lock.json: Restored from dev
- Update ISettingProvider to support CreateSettingPanelAvalonia
- Create native Avalonia settings UI for Program Plugin (ProgramSetting.axaml)
- Implement ProgramSettingViewModel using CommunityToolkit.Mvvm
- Update PluginsSettingsViewModel to detect and load native Avalonia settings
- Replace ListBox with ItemsControl in PluginsSettingsPage to fix auto-scroll issues when expanding settings
- Align Avalonia package versions (11.2.3) across projects to fix type load errors