feat: add video job cancellation functionality and error tracking in generated videos

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

frontend/app/templates/admin.html

@@ -1,6 +1,6 @@
 {% extends "base.html" %} {% block title %}Admin — All You Can GET AI{% endblock
 %} {% block content %}
-<div class="card">
+<div class="card admin-page">
   <h1>Admin Dashboard</h1>
 
   {% if stats %}