feat(tickets): open, comment and resolve tickets from the UI and MCP; known issues on alerts and anomalies (#6351, #6352)

A ticket records a known problem: title, area, hosts, subject, description,
links to alert rules and anomalies, and a log of comments, edits, resolving
and reopening. Opening, resolving (with the resolution as the note) and
reopening go on the timeline; every step is audited, and the audit rows stay
off the timeline.

An alert or anomaly an open ticket covers (by link, by subject, or a
host-wide ticket on the host itself) shows a Known issue badge, and offers
"Open a ticket" prefilled from its rule or anomaly when none does. Hosts,
monitors and containers get a Known issues card.

MCP: list_tickets, get_ticket (viewer); open_ticket, update_ticket,
comment_ticket, resolve_ticket, reopen_ticket (operator). list_alerts and
list_anomalies carry known_issue; get_overview, get_host, get_monitor and
get_container carry open_tickets. Also update_change and delete_change for
changes recorded by hand (author or admin).

Tickets are left out of backups, like the timeline (2026-10-15 ruling).

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

steward/templates/tickets/list.html

@@ -0,0 +1,62 @@
+{# tickets/list.html — known problems, open first (tickets.service): each with
+   what it is about, its area, who opened it and when, and how many comments
+   it has; resolved ones say who resolved them and how. #}
+{% extends "base.html" %}
+{% from "_macros.html" import page_header, empty_state, status_badge %}
+{% block title %}Tickets — Steward{% endblock %}
+{% block content %}
+{% call page_header("Tickets", "Known problems, open until someone resolves them. Opening and resolving one goes on the timeline.") %}
+  {% if session.user_role in ('operator', 'admin') %}<a class="btn btn-sm" href="/tickets/new{% if host %}?host={{ host|urlencode }}{% endif %}">Open a ticket</a>{% endif %}
+{% endcall %}
+
+<p class="page-verdict">
+  {%- if open_count %}<strong class="tone-warn">{{ open_count }} open</strong>{% else %}<strong class="tone-ok">No open tickets</strong>{% endif %}
+  {%- if host %} · on <a href="/timeline/?host={{ host|urlencode }}">{{ host }}</a> · <a href="/tickets/?status={{ status }}">every host</a>{% endif %}
+</p>
+
+<nav class="filter-bar" aria-label="Which tickets">
+  {% for key, label in (("open", "Open"), ("resolved", "Resolved"), ("all", "All")) %}
+  <a class="btn btn-sm {{ 'btn-ghost' if status != key }}"{% if status == key %} aria-current="page"{% endif %}
+     href="/tickets/?status={{ key }}{% if host %}&amp;host={{ host|urlencode }}{% endif %}">{{ label }}</a>
+  {% endfor %}
+</nav>
+
+{% if tickets %}
+<div class="card-flush">
+  <table class="table">
+    <thead>
+      <tr>
+        <th>Ticket</th>
+        <th>Where</th>
+        <th>Area</th>
+        <th>Opened ({{ tz_label() }})</th>
+        <th>State</th>
+      </tr>
+    </thead>
+    <tbody>
+      {% for t in tickets %}
+      <tr>
+        <td>
+          <a href="/tickets/{{ t.id }}"><span class="tone-dim">#{{ t.id }}</span> {{ t.title }}</a>
+          {%- if counts.get(t.id) %}<div class="field-hint">{{ counts[t.id] }} comment{{ "s" if counts[t.id] != 1 }}</div>{% endif %}
+        </td>
+        <td>
+          {%- for h in t.hosts %}<a href="/tickets/?host={{ h|urlencode }}&amp;status={{ status }}">{{ h }}</a>{{ ", " if not loop.last }}{% endfor -%}
+          {%- if t.subject %}{% if t.hosts %}<br>{% endif %}<span class="field-hint">{{ t.subject }}</span>{% endif -%}
+          {%- if not t.hosts and not t.subject %}<span class="tone-dim">—</span>{% endif -%}
+        </td>
+        <td class="nowrap"><span class="chip">{{ labels.get(t.area, t.area) }}</span></td>
+        <td class="nowrap">{{ t.opened_at|when }}<div class="field-hint">{{ t.opened_by }}</div></td>
+        <td>
+          {{ status_badge(t.status) }}
+          {%- if t.status == 'resolved' %}<div class="field-hint">{{ t.resolved_by }}, {{ t.resolved_at|when }}</div>{% endif %}
+        </td>
+      </tr>
+      {% endfor %}
+    </tbody>
+  </table>
+</div>
+{% else %}
+<div class="card">{{ empty_state({"open": "No open tickets.", "resolved": "No ticket has been resolved yet.", "all": "No tickets yet."}[status]) }}</div>
+{% endif %}
+{% endblock %}