Disable SWC loose mode for Stimulus compatibility

The loose: true mode in Shakapacker's default SWC config can cause issues
with class method binding. Explicitly setting loose: false ensures that
Stimulus controller methods are properly bound and can respond to events
like turbo:submit-end.

Author: justin808

config/swc.config.js

@@ -10,6 +10,8 @@ module.exports = {
       }
     },
     // Preserve ES6 classes for Stimulus compatibility
-    keepClassNames: true
+    keepClassNames: true,
+    // Disable loose mode to ensure proper class method binding for Stimulus
+    loose: false
   }
 };