feat: implement video job management with retry and delete functionality, enhance video generation status tracking

Co-authored-by: Copilot <copilot@github.com>

frontend/app/templates/generate_video.html

@@ -155,9 +155,9 @@ AI{% endblock %} {% block content %}
   {% endif %} {% if result %}
   <div class="result">
     <h2>Video job</h2>
-    <p>Job ID: <code>{{ result.id }}</code></p>
-    {% if result.status in ('queued', 'processing') and result.polling_url %}
-    <div id="video-poll-status" data-polling-url="{{ result.polling_url }}">
+    <p>Job ID: <code>{{ result.db_id or result.id }}</code></p>
+    {% if result.status in ('queued', 'processing') and result.db_id %}
+    <div id="video-poll-status" data-video-id="{{ result.db_id }}">
       <p>
         <span id="poll-status-text"
           >Status: <strong>{{ result.status }}</strong></span