Surface full error info on transcribe failure

mega-asr.js

@@ -590,9 +590,12 @@ document.getElementById("transcribe-btn").addEventListener("click", async () =>
     const elapsed = (performance.now() - t0) / 1000;
     renderResult(text, refText, `INT4 ONNX · ${state.device} · ${elapsed.toFixed(1)}s`);
   } catch (e) {
-    log("TRANSCRIBE FAILED: " + e.message);
+    const msg = (e && (e.message || e.toString())) || JSON.stringify(e) || "(no error info)";
+    const stk = (e && e.stack) ? e.stack.split("\n").slice(0, 3).join(" | ") : "(no stack)";
+    log("TRANSCRIBE FAILED: " + msg);
+    log("stack: " + stk);
     console.error(e);
-    renderResult("", refText, `error: ${e.message}`);
+    renderResult("", refText, `error: ${msg}`);
   } finally {
     document.getElementById("transcribe-btn").disabled = false;
   }