fix(ui): delete prompts use data-confirm, so a quote in a name no longer runs script (#5099)

#5099 "A name containing a quote runs script when an admin clicks Delete".
Inline handlers like onclick="return confirm('Delete {{ rule.name }}?')" are
HTML-decoded before the JavaScript is parsed, so autoescaping did not stop a
name such as  x');fetch(…);//  from running.

- Every prompt (22 handlers, plus the docker prune and token revoke ones)
  is now data-confirm="…", read through dataset by one submit listener in
  base.html; nothing rendered is parsed as JavaScript.
- The remaining inline handlers take integers only (|int), and the time
  range buttons pass this.dataset.range.
- tests/test_inline_handlers.py fails on any {{ }} in an inline handler that
  is not |int, with a self-test; tests/_templates.py is the one template
  walker the template guards now share.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/docker/templates/docker/disk.html

@@ -53,20 +53,17 @@
     {% if ansible_available and g.has_target %}
     <div style="display:flex;flex-wrap:wrap;gap:0.5rem;align-items:center;">
       <form method="post" action="/plugins/docker/disk/{{ g.host_id }}/prune" style="margin:0;"
-            data-msg="Remove all STOPPED containers on {{ g.host_name|e }}? This cannot be undone."
-            onsubmit="return confirm(this.dataset.msg);">{{ csrf_field() }}
+            data-confirm="Remove all STOPPED containers on {{ g.host_name }}? This cannot be undone.">{{ csrf_field() }}
         <input type="hidden" name="target" value="containers">
         <button type="submit" class="btn btn-sm">Prune stopped containers</button>
       </form>
       <form method="post" action="/plugins/docker/disk/{{ g.host_id }}/prune" style="margin:0;"
-            data-msg="Remove ALL unused images on {{ g.host_name|e }} (docker image prune -a)? Any image not used by a container is deleted."
-            onsubmit="return confirm(this.dataset.msg);">{{ csrf_field() }}
+            data-confirm="Remove ALL unused images on {{ g.host_name }} (docker image prune -a)? Any image not used by a container is deleted.">{{ csrf_field() }}
         <input type="hidden" name="target" value="images">
         <button type="submit" class="btn btn-sm">Prune unused images</button>
       </form>
       <form method="post" action="/plugins/docker/disk/{{ g.host_id }}/prune" style="margin:0;"
-            data-msg="Run a full system prune on {{ g.host_name|e }}? Removes stopped containers, unused networks, dangling images and build cache."
-            onsubmit="return confirm(this.dataset.msg);">{{ csrf_field() }}
+            data-confirm="Run a full system prune on {{ g.host_name }}? Removes stopped containers, unused networks, dangling images and build cache.">{{ csrf_field() }}
         <input type="hidden" name="target" value="system">
         <button type="submit" class="btn btn-sm btn-danger">System prune…</button>
       </form>