Resolution dropdown, list-focus preservation, unified dark theme, startup logging, and memory map

- Bottom-bar resolution dropdown (1080p60/1080p30/720p60/480p30) with tooltip
  on finding upload bandwidth; disabled while live; no in-app speed test
- FocusPreservingListBox keeps selection/focus coherent when a selected
  scene/source is deleted (skip hidden scenes; leave list when empty)
- Themes/Controls.xaml: single dark-theme dictionary merged once in App.xaml;
  custom ComboBox template fixes SelectionBoxItem rendering; GoLiveWindow and
  ReuseImageDialog consolidated onto shared styles
- AppLog file logger + AppDomain/Dispatcher exception hooks; checkpointed
  MainWindow/VM/dialog constructors (caught MenuItemRole.Separator XAML crash)
- Memory map: schema.md conventions, per-directory index.md, updated ai.md/
  TASKS.md/README.md (OAuth creds real; token persistence still pending)

README.md

@@ -41,8 +41,14 @@ dotnet run
 
 | Path | Role |
 |------|------|
-| `Models/` | Scene, Source, StreamConfig, StreamHealth, YouTube channel/chat |
-| `ViewModels/` | MainViewModel — scenes, stream controls, chat |
-| `Services/` | YouTubeAuthService (OAuth2), YouTubeStreamService (broadcast/health), YouTubeChatService (chat polling) |
-| `Helpers/` | ViewModelBase, RelayCommand |
+| `Models/` | Scene, Source, QualityOption, StreamConfig, StreamHealth, YouTube channel/chat |
+| `ViewModels/` | MainViewModel — scenes, stream controls, chat; GoLiveViewModel, ReuseImageViewModel |
+| `Services/` | YouTubeAuthService (OAuth2), YouTubeStreamService (broadcast/health), YouTubeChatService (chat polling), LayoutStore (SQLite) |
+| `Helpers/` | ViewModelBase, RelayCommand, ImageCache, AppLog, FocusPreservingListBox, OAuthCredentials |
+| `Themes/` | `Controls.xaml` — the dark-theme control styles, merged once in `App.xaml` |
 | `MainWindow.xaml` | Dark-theme main UI: scene/source panel, preview, chat, status bar |
+
+## Docs (memory map)
+
+`schema.md` defines the conventions; `ai.md` is the AI/session guide;
+`TASKS.md` is the task queue. Each code directory carries an `index.md`.