Helpers — index

Cross-cutting utilities. See schema.md for the memory-map conventions.

File	Purpose
`ViewModelBase.cs`	`INotifyPropertyChanged` + `SetProperty<T>()` — base for all ViewModels
`RelayCommand.cs`	`ICommand` implementation for all button actions
`AppLog.cs`	File logger to `%APPDATA%\ytLlive\startup.log`; startup checkpoints + unhandled-exception capture (the crash this map is named for)
`FocusPreservingListBox.cs`	`ListBox` subclass that keeps selection/focus coherent when the selected item is deleted; `IsSelectable` predicate skips hidden scenes; drag-reorder guard
`OAuthCredentials.cs`	Baked-in Google OAuth client ID/secret (desktop app; loopback callback)
`TokenStore.cs`	DPAPI-protected OAuth session persistence (`%APPDATA%\ytLlive\ytLlive.auth`, CurrentUser scope); `Save`/`Load`/`Clear` — sign-in survives restarts
`ImageCache.cs`	Image byte caching (assets live in the DB)
`InverseBoolToVisibilityConverter.cs` / `NotNullToVisibilityConverter.cs`	XAML value converters for visibility bindings
`CameraConflictProbe.cs`	Best-effort diagnostic: when a camera won't start, enumerates running processes known to hold cameras (OBS, Zoom, Teams, NVIDIA Broadcast, browsers, etc.) — Windows doesn't expose "which process has this device" via any public API, so this is a suspect list, not a verdict

Related: Themes/Controls.xaml styles the lists this class backs; Models/index.md and ViewModels/index.md for the objects it works on.