Restructuring and refactoring

packages/browser-extension/static/sandbox.js

@@ -0,0 +1,12 @@
+// Minimal sandbox.js - just listens for sandbox-load and writes the content
+window.addEventListener("message", (event) => {
+	if (event.data.type === "sandbox-load") {
+		// Write the complete HTML (which includes runtime + user code)
+		document.open();
+		document.write(event.data.code);
+		document.close();
+	}
+});
+
+// Signal ready to parent
+window.parent.postMessage({ type: "sandbox-ready" }, "*");