feat: sandbox plugins in null-origin iframes with postMessage RPC

app/plugin-sandbox/page.tsx

@@ -0,0 +1,7 @@
+import { SandboxRuntime } from '@/lib/plugin-sandbox/runtime';
+
+export const dynamic = 'force-static';
+
+export default function PluginSandboxPage() {
+  return <SandboxRuntime />;
+}