Skip system models in JS concrete class generation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/RSpade/Core/Bundle/BundleCompiler.php

@@ -1211,11 +1211,16 @@ class BundleCompiler
 
             $class_name = $manifest_files[$relative]['class'];
 
-            // Check if this class is a subclass of Rsx_Model_Abstract (but not system models)
+            // Check if this class is a subclass of Rsx_Model_Abstract
             if (!Manifest::php_is_subclass_of($class_name, 'Rsx_Model_Abstract')) {
                 continue;
             }
 
+            // Skip system models (internal framework models not exposed to JavaScript)
+            if (Manifest::php_is_subclass_of($class_name, 'Rsx_System_Model_Abstract')) {
+                continue;
+            }
+
             // Skip abstract model classes - only concrete models get JS stubs
             if (Manifest::php_is_abstract($class_name)) {
                 continue;