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>

steward/templates/ansible/playbook_editor.html

@@ -54,7 +54,7 @@
 
 {% if editing %}
 <form method="post" action="/ansible/playbooks/delete" style="margin-top:1rem;"
-      onsubmit="return confirm('Delete {{ playbook_path }}?');">{{ csrf_field() }}
+      data-confirm="Delete {{ playbook_path }}?">{{ csrf_field() }}
   <input type="hidden" name="source_name" value="{{ source_name }}">
   <input type="hidden" name="playbook_path" value="{{ playbook_path }}">
   <button type="submit" class="btn btn-danger btn-sm">Delete playbook</button>