Fix play mode test scene jumping issue

This commit fixes an issue where play mode tests would jump to the init scene but not run any tests.

Changes:
- Wrap TestRunnerCallbacks.IsRunningTests check with #if UNITY_INCLUDE_TESTS in ChangeScene.cs
  This ensures the test runner check is only performed when test framework is available
- Add test assembly reference to JEngine.Core.Editor.asmdef (GUID:0acc523941302664db1f4e527237feb3)
- Update .gitignore to exclude Claude-generated files

The root cause was that ChangeScene.cs was trying to check TestRunnerCallbacks.IsRunningTests
without verifying the test framework was available, which could cause the check to fail or
not work properly during play mode tests.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: JasonXuDeveloper

.gitignore

@@ -16,3 +16,12 @@ UnityProject/Build/*
 /UnityProject/UserSettings/Layouts
 /UnityProject/HybridCLRData
 /UnityProject/UserSettings
+
+# Auto Claude generated files
+.auto-claude/
+.auto-claude-security.json
+.auto-claude-status
+.claude_settings.json
+.worktrees/
+.security-key
+logs/security/

UnityProject/Packages/com.jasonxudeveloper.jengine.core/Editor/JEngine.Core.Editor.asmdef

@@ -11,7 +11,8 @@
         "GUID:f51ebe6a0ceec4240a699833d6309b23",
         "GUID:e34a5702dd353724aa315fb8011f08c3",
         "GUID:3743e71edcd5bd8499007797ef02cbfb",
-        "GUID:27619889b8ba8c24980f49ee34dbb44a"
+        "GUID:27619889b8ba8c24980f49ee34dbb44a",
+        "GUID:0acc523941302664db1f4e527237feb3"
     ],
     "includePlatforms": [
         "Editor"

UnityProject/Packages/com.jasonxudeveloper.jengine.core/Editor/Misc/ChangeScene.cs

@@ -12,11 +12,13 @@ internal static class ChangeScene
         [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
         private static void DoChange()
         {
+#if UNITY_INCLUDE_TESTS
             // Skip scene change when running Play Mode tests
             if (TestRunnerCallbacks.IsRunningTests)
             {
                 return;
             }
+#endif
 
             var jump = Settings.Instance.jumpStartUp;
             if (!jump) return;