chore(unity): 固定Unity CLI Loop本地包并移除UnitySkills依赖

Client/Packages/io.github.hatayama.uloopmcp/Editor/Shared/Models/DynamicCompilationBackendKind.cs

@@ -0,0 +1,10 @@
+namespace io.github.hatayama.uLoopMCP
+{
+    public enum DynamicCompilationBackendKind
+    {
+        Unknown = 0,
+        SharedRoslynWorker = 1,
+        OneShotRoslyn = 2,
+        AssemblyBuilderFallback = 3
+    }
+}