Scene strip tile artwork + on-air indicator (creator ruling 2026-10-10). Top-bar tiles now carry their own art: each canonical scene's tile is a per-scene CRT-styled image stored in the internal DB (Scene.ThumbnailAssetId - additive migration, seeded at heal from the creator's five Downloads JPGs via SceneThumbnailSeedPaths), and the preview pane keeps rendering the scene's ORIGINAL background - never the tiles. One shared on-air image (Gemini 4zajyl...jpg) replaces the staged scene's tile and follows the scene swap ('the on-air screen jumps around the top bar as the user swaps scenes'): stored as an Asset BLOB tracked by the OnAirImageAssetId Setting (EnsureOnAirImage, same contract as the alert clip) with MainViewModel.OnAirSeedPath override; RefreshSnapshotsAsync shows it for the staged scene, otherwise thumbnail-or-background art, and a staged Live with no on-air art still falls back to the green placeholder (minis never render live captures). Removed the 6px #22c55e rectangle in PreviewPane's backdrop ('green outline around the preview screen' that surfaced when a scene had no background) - the outer PreviewGlow red border is the real live signal. Doubled the scene-tile labels (FontSize 10 -> 20). Fixed a real bug this surfaced: Save()'s Asset pruner only kept Source/alert-clip rows, so the first save would have DELETED the seeded tile + on-air assets - the keep-set now includes Scene.ThumbnailAssetId and the OnAirImageAssetId Setting. New Settings/Load/Save migrations + SceneThumbnailTests (4 tests: seeded tile in strip, preview keeps original bg, Live-staged tile, no-seed fallback, on-air swap + persistence). 427 pass, 0 build warnings. (Unit: strip tiles + on-air)

Models/Scene.cs

@@ -72,6 +72,14 @@ public class Scene : INotifyPropertyChanged
 
     public bool IsChatScene { get; init; }
 
+    /// <summary>
+    /// Asset-table id of this scene's top-strip tile artwork. The tile is a
+    /// separate image from the scene's background: the preview pane keeps
+    /// rendering the scene's original background, the strip shows this instead.
+    /// Null = the strip falls back to the background art (creator ruling 2026-10-10).
+    /// </summary>
+    public string? ThumbnailAssetId { get; set; }
+
     private BitmapSource? _snapshot;
 
     /// <summary>