Fix: iframe caching issues

Author: shirsho-12

src/commands/showPanel.tsx

@@ -40,9 +40,11 @@ export async function showPanel(
     undefined,
     context.subscriptions,
   );
-
-  const iframeUrl = new URL(route ?? "/playground", config.frontendBaseUrl)
-    .href;
+  
+  // Cache-busting: append a short-lived query param so VS Code picks up the latest frontend build.
+  const urlObj = new URL(route ?? "/playground", config.frontendBaseUrl);
+  urlObj.searchParams.set("v", String(Date.now()));
+  const iframeUrl = urlObj.href;
 
   setWebviewContent(
     messageHandler.panel,