Sync offline cache on every page load, not just every 2 minutes

Online-side mutations (e.g. deleting a tag) only update the server, not
IndexedDB, so a throttled background sync could leave the offline cache
stale for up to two minutes. Going offline in that window resurrected
deleted/stale data (e.g. a deleted tag reappearing). Removing the throttle
so every real page load pulls fresh state keeps the offline cache in
sync with whatever was just done online.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

templates/base.html

@@ -148,8 +148,8 @@
     {% endblock %}
 
     <script src="{% static 'js/offline-db.js' %}?v=7"></script>
-    <script src="{% static 'js/offline-sync.js' %}?v=9"></script>
-    <script src="{% static 'js/app.js' %}?v=8"></script>
+    <script src="{% static 'js/offline-sync.js' %}?v=10"></script>
+    <script src="{% static 'js/app.js' %}?v=9"></script>
     {% block extra_js %}{% endblock %}
 </body>
 </html>