ECS refactor: new ComponentSet, serialization, generators

Major ECS API overhaul: added ComponentSet, refactored ComponentRegistry, and updated all entity/component creation methods. Introduced robust custom serialization infrastructure and per-component source generators for registration and (de)serialization. Updated editor, engine, and test code to use new APIs. Improved code quality, naming, and performance throughout. Removed obsolete code and updated dependencies.

Ghost.Editor.Core/AssetHandle/AssetDatabase.cs

@@ -4,7 +4,7 @@ namespace Ghost.Editor.Core.AssetHandle;
 
 public static partial class AssetDatabase
 {
-    private static FileSystemWatcher? _watcher;
+    private static FileSystemWatcher? s_watcher;
 
     private static readonly Dictionary<Guid, string> s_assetPathLookup = new();
 
@@ -22,7 +22,7 @@ public static partial class AssetDatabase
         }
 
         AssetsDirectory = new DirectoryInfo(Path.Combine(Path.GetDirectoryName(ProjectService.CurrentProject.Path)!, ProjectService.ASSETS_FOLDER));
-        _watcher = new FileSystemWatcher
+        s_watcher = new FileSystemWatcher
         {
             Path = AssetsDirectory.FullName,
             IncludeSubdirectories = true,