Add audiowidget endpoint: Blueprint renders audiowidget.tmpl, PaneCP fetches it on synthesis completion

templates/vue3_neusik/index.html

@@ -14,8 +14,9 @@ window.NEUSICIAN_URLS = {
     astlog:  "{{ url_for('astlog') }}",
     score:   "{{ url_for('score') }}",
     status:  "{{ url_for('statusjson') }}",
-    result:  "{{ url_for('send_audio_generated') }}",
-    submit:  "{{ url_for('public-yaml-acceptor') }}"
+    result:      "{{ url_for('send_audio_generated') }}",
+    submit:      "{{ url_for('public-yaml-acceptor') }}",
+    audiowidget: "{{ url_for('vue3_neusik.audiowidget') }}"
 };
 </script>
 <script type="importmap">