feat(alerts): Steward's own confirm dialog, a verdict-first rules list, and a rule page in three sections (#5314, #5315, #5317)

Confirm dialog (#5314):
- Every data-confirm form now asks in one native <dialog> (base.html + static/confirm.js)
  instead of window.confirm.
- The question becomes the heading and what follows it the detail; the act's
  button is named after the form's own button; Cancel has the focus and Esc
  backs out. Optional data-confirm-title/-detail/-action/-dismiss attributes.
- All 27 existing uses work as they are. Cancelling a run says 'Keep running'.

Alerts list (#5315):
- A verdict line (what is firing, how many rules, where notifications go,
  or 'notifies nobody yet' with a link) replaces the empty Active card.
- Each rule's name opens it; rows show 'last fired' and fold fire/clear into
  the condition; History and Disable stay; Delete leaves the list.
- .docker-verdict becomes the shared .page-verdict.

Rule page (#5317):
- Named for the rule (title and crumb), with when it last fired and how many
  changes of state it holds.
- Three sections: what it watches, when it fires (checks side by side,
  seconds echoed as a duration), what happens (where notifications go, no-data,
  the playbook, whose fields stay folded until ticked).
- Delete at the foot, behind the dialog, saying its history goes with it.

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

steward/templates/alerts/_active.html

@@ -1,9 +1,26 @@
-{# alerts/_active.html — the Alerts page's Active section, polled on its own:
+{# alerts/_active.html — the Alerts page's verdict and Active section, polled
+   on their own (#5315): one line that says what is firing, how many rules
+   there are and where their notifications go; then the alerts themselves,
    firing first, then no data, then acknowledged, then pending
    (alert_svc.active_rows). An acknowledged alert says how long it has been
    breaching, and apart from that who acknowledged it and when. #}
-{% from "_macros.html" import status_badge, empty_state %}
+{% from "_macros.html" import status_badge %}
 {% set can_edit = session.user_role in ('operator', 'admin') %}
+{% set words = {"firing": "firing", "no_data": "silent", "acknowledged": "acknowledged", "pending": "pending"} %}
+<p class="page-verdict">
+  {%- set firing = active|selectattr("label", "equalto", "firing")|list|length %}
+  {%- if firing %}<strong class="tone-crit">{{ firing }} firing</strong>
+  {%- elif active %}<strong class="tone-warn">Nothing is firing</strong>
+  {%- else %}<strong class="tone-ok">Nothing is firing</strong>{% endif %}
+  {%- for key in ("no_data", "acknowledged", "pending") %}
+  {%- set n = active|selectattr("label", "equalto", key)|list|length %}
+  {%- if n %} · <span class="tone-warn">{{ n }} {{ words[key] }}</span>{% endif %}
+  {%- endfor %}
+  {%- if rules_total %} · {{ rules_total }} rule{{ "s" if rules_total != 1 }}{% if rules_off %}, {{ rules_off }} off{% endif %}{% endif %}
+  {%- if notify %} · notifies {{ notify|join(" and ") }}
+  {%- else %} · <span class="tone-warn" title="No email server with recipients and no webhook URL is set, so an alert that fires tells no one">notifies nobody yet</span>
+  {%- if session.user_role == 'admin' %} — <a href="/settings/notifications/">set up email or a webhook</a>{% endif %}{% endif %}
+</p>
 {% if active %}
 <h2 class="section-title" style="margin-bottom:1rem;">Active</h2>
 <div class="card-flush" style="margin-bottom:2rem;">
@@ -46,6 +63,4 @@
         </tbody>
     </table>
 </div>
-{% else %}
-<div class="card" style="margin-bottom:2rem;">{{ empty_state("No active alerts. Every rule is quiet.") }}</div>
 {% endif %}