[fix](trx-frontend-http): defer decode SSE until plugins load

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -5992,7 +5992,13 @@ function connectDecode() {
     }
   };
 }
-connectDecode();
+if (document.readyState === "complete") {
+  connectDecode();
+} else {
+  window.addEventListener("load", () => {
+    connectDecode();
+  }, { once: true });
+}
 
 // Release PTT on page unload to prevent stuck transmit
 window.addEventListener("beforeunload", () => {