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/ai_access/index.html

@@ -59,7 +59,7 @@
             <td class="td-actions">
               {% if row.state == 'active' %}
               <form method="post" action="/ai-access/tokens/{{ t.id }}/revoke" style="margin:0;"
-                    onsubmit='return confirm({{ ("Revoke “" ~ t.name ~ "”? Any client using it stops working immediately.")|tojson }})'>{{ csrf_field() }}
+                    data-confirm="Revoke “{{ t.name }}”? Any client using it stops working immediately.">{{ csrf_field() }}
                 <button type="submit" class="btn btn-danger btn-sm">Revoke</button>
               </form>
               {% endif %}