fix: validate worker action with Map.has and a function check

Follow CodeQL's recommended pattern for js/unvalidated-dynamic-method-call:
check the name with Map.prototype.has and verify the handler is a
function before calling it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: bajrangCoder

plugin.zip

@@ -123,9 +123,11 @@ __builtins__.input = input
 );
 
 self.onmessage = async (e) => {
-	const handler = actions.get(e.data.action);
+	const { action } = e.data;
+	if (!actions.has(action)) return;
 
-	if (handler) {
+	const handler = actions.get(action);
+	if (typeof handler === "function") {
 		await handler(e.data);
 	}
 };