Add game scene and level catalog interfaces, and implement scene management in AppRoot

game/services/LevelService.cs

@@ -1,6 +1,21 @@
+using Mr.BrickAdventures.game.repositories;
+
 namespace Mr.BrickAdventures.game.services;
 
 public sealed class LevelService
 {
+    private readonly LevelRepository _levels;
+    public LevelService(LevelRepository levels) => _levels = levels;
     
+    public int CompleteAndAdvance() {
+        var cur = _levels.Current;
+        _levels.Complete(cur);
+        var next = cur + 1;
+        _levels.SetCurrent(next);
+        return next;
+    }
+    
+    public void StartNew() {
+        _levels.Load(new LevelState { Current = 0, Unlocked = new [] { 0 }, Completed = [] });
+    }
 }