Add stat cards, lt-frame alert queue, and timeline for resolved alerts

- Four lt-stat-card widgets (Critical, Warning, Hosts, Resolved 24h)
  below the status bar; Critical card pulses red when count > 0
- Clicking Critical or Warning card filters the events table by severity
- Events table wrapped in lt-frame with ASCII corner ornaments and
  lt-section-header; filter bar moved to lt-toolbar with lt-search icon
- Recently Resolved table replaced with lt-timeline component
- updateStatusBar() and updateHostGrid() keep stat card values live

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

static/app.js

@@ -89,6 +89,14 @@ function updateStatusBar(summary, lastCheck, daemonOk) {
     alertBadge.style.display = total ? '' : 'none';
   }
 
+  // Update stat cards
+  const scCrit = document.getElementById('stat-critical-val');
+  const scWarn = document.getElementById('stat-warning-val');
+  if (scCrit) scCrit.textContent = critCount;
+  if (scWarn) scWarn.textContent = warnCount;
+  const statCritCard = document.getElementById('stat-critical');
+  if (statCritCard) statCritCard.classList.toggle('lt-stat-card--alert', critCount > 0);
+
   // Stale data banner: warn if last_check is older than 15 minutes
   let staleBanner = document.getElementById('stale-banner');
   if (lastCheck) {
@@ -112,6 +120,9 @@ function updateStatusBar(summary, lastCheck, daemonOk) {
 }
 
 function updateHostGrid(hosts) {
+  const scHosts = document.getElementById('stat-hosts-val');
+  if (scHosts) scHosts.textContent = Object.keys(hosts).length;
+
   for (const [name, host] of Object.entries(hosts)) {
     const card = document.querySelector(`.host-card[data-host="${CSS.escape(name)}"]`);
     if (!card) continue;

static/style.css

@@ -995,6 +995,17 @@
 .diag-pulse-link a { color: var(--cyan); }
 .diag-pulse-link a:hover { text-shadow: var(--glow-cyan); }
 
+/* ── Stat card alert variant (pulsing border when critical > 0) ─── */
+.lt-stat-card--alert {
+  border-color: var(--red) !important;
+  box-shadow: 0 0 8px rgba(255,45,85,.25) !important;
+  animation: topo-pulse-down 2s ease-in-out infinite;
+}
+.lt-stat-card--alert::before { background: var(--red); box-shadow: var(--glow-red); }
+
+/* ── lt-frame inside g-section: no extra bottom margin ────────────── */
+.g-section > .lt-frame { margin-bottom: 0; }
+
 /* ── Responsive ───────────────────────────────────────────────────── */
 @media (max-width: 768px) {
   .host-grid         { grid-template-columns: 1fr; }

templates/index.html

@@ -26,6 +26,42 @@
   </div>
 </div>
 
+<!-- ── Stats summary cards ──────────────────────────────────────────── -->
+<div class="lt-stats-grid">
+  <div class="lt-stat-card{% if summary.critical %} lt-stat-card--alert{% endif %}"
+       id="stat-critical" role="button" tabindex="0"
+       data-stat-filter="critical" aria-label="{{ summary.critical or 0 }} critical alerts">
+    <span class="lt-stat-icon" aria-hidden="true" style="color:var(--red);text-shadow:var(--glow-red)">●</span>
+    <div class="lt-stat-info">
+      <span class="lt-stat-value" id="stat-critical-val" style="color:var(--red)">{{ summary.critical or 0 }}</span>
+      <span class="lt-stat-label">Critical</span>
+    </div>
+  </div>
+  <div class="lt-stat-card"
+       id="stat-warning" role="button" tabindex="0"
+       data-stat-filter="warning" aria-label="{{ summary.warning or 0 }} warning alerts">
+    <span class="lt-stat-icon" aria-hidden="true" style="color:var(--amber)">●</span>
+    <div class="lt-stat-info">
+      <span class="lt-stat-value" id="stat-warning-val" style="color:var(--amber)">{{ summary.warning or 0 }}</span>
+      <span class="lt-stat-label">Warning</span>
+    </div>
+  </div>
+  <div class="lt-stat-card" id="stat-hosts" aria-label="Monitored hosts">
+    <span class="lt-stat-icon" aria-hidden="true" style="color:var(--cyan)">⬡</span>
+    <div class="lt-stat-info">
+      <span class="lt-stat-value" id="stat-hosts-val" style="color:var(--cyan)">{{ snapshot.hosts | length }}</span>
+      <span class="lt-stat-label">Hosts</span>
+    </div>
+  </div>
+  <div class="lt-stat-card" id="stat-resolved" aria-label="{{ recent_resolved | length }} alerts resolved in last 24 hours">
+    <span class="lt-stat-icon" aria-hidden="true" style="color:var(--green);text-shadow:var(--glow)">✔</span>
+    <div class="lt-stat-info">
+      <span class="lt-stat-value" id="stat-resolved-val" style="color:var(--green)">{{ recent_resolved | length }}</span>
+      <span class="lt-stat-label">Resolved 24h</span>
+    </div>
+  </div>
+</div>
+
 <!-- ── Network topology + host grid ───────────────────────────────── -->
 <section class="g-section">
   <div class="g-section-header">
@@ -282,19 +318,25 @@
     <h2 class="g-section-title">Active Alerts</h2>
     <span class="g-section-badge" id="alert-count-badge"
           {% if not summary.critical and not summary.warning %}style="display:none"{% endif %}>{{ (summary.critical or 0) + (summary.warning or 0) }}</span>
-    <div class="g-section-actions">
-      <div class="events-filter-bar">
-        <input type="search" class="lt-input lt-input-sm" id="events-search"
+  </div>
+  <div class="lt-toolbar">
+    <div class="lt-toolbar-left">
+      <div class="lt-search">
+        <input type="search" class="lt-input lt-search-input" id="events-search"
                placeholder="Filter by target, type, description…" autocomplete="off">
-        <div class="sev-pills">
-          <button type="button" class="pill active" data-sev="">All</button>
-          <button type="button" class="pill" data-sev="critical">Critical</button>
-          <button type="button" class="pill" data-sev="warning">Warning</button>
-        </div>
+      </div>
+      <div class="sev-pills">
+        <button type="button" class="pill active" data-sev="">All</button>
+        <button type="button" class="pill" data-sev="critical">Critical</button>
+        <button type="button" class="pill" data-sev="warning">Warning</button>
       </div>
     </div>
   </div>
-  <div id="events-table-wrap">
+  <div class="lt-frame">
+    <span class="lt-frame-bl">&#x255A;</span>
+    <span class="lt-frame-br">&#x255D;</span>
+    <div class="lt-section-header">Alert Queue</div>
+    <div id="events-table-wrap">
     {% if events %}
     {% if total_active is defined and total_active > events|length %}
     <div class="pagination-notice">Showing {{ events|length }} of {{ total_active }} active alerts &mdash; <a href="/api/events?limit=1000">view all via API</a></div>
@@ -364,7 +406,8 @@
       <div class="lt-empty-state-title">No active alerts</div>
     </div>
     {% endif %}
-  </div>
+    </div><!-- /#events-table-wrap -->
+  </div><!-- /.lt-frame -->
 </section>
 
 <!-- ── Recently Resolved (last 24h) ───────────────────────────────── -->
@@ -374,34 +417,24 @@
     <h2 class="g-section-title">Recently Resolved</h2>
     <span class="g-section-badge g-section-badge-resolved">{{ recent_resolved | length }} in last 24h</span>
   </div>
-  <div class="lt-table-wrap">
-    <table class="lt-table">
-      <caption class="lt-sr-only">Recently resolved alerts</caption>
-      <thead>
-        <tr>
-          <th>Sev</th>
-          <th>Type</th>
-          <th>Target</th>
-          <th>Detail</th>
-          <th>Resolved</th>
-          <th>Duration</th>
-        </tr>
-      </thead>
-      <tbody>
-        {% for e in recent_resolved %}
-        <tr class="row-resolved">
-          <td><span class="lt-badge badge-resolved">{{ e.severity }}</span></td>
-          <td>{{ e.event_type | replace('_', ' ') }}</td>
-          <td><strong>{{ e.target_name }}</strong></td>
-          <td>{{ e.target_detail or '–' }}</td>
-          <td class="ts-cell">
-            <span class="event-age" data-ts="{{ e.resolved_at }}">{{ e.resolved_at }}</span>
-          </td>
-          <td class="ts-cell event-duration" data-first="{{ e.first_seen }}" data-resolved="{{ e.resolved_at }}">–</td>
-        </tr>
-        {% endfor %}
-      </tbody>
-    </table>
+  <div class="lt-timeline">
+    {% for e in recent_resolved %}
+    {%- set dot_cls = 'lt-timeline-item--green' if e.severity == 'info' else 'lt-timeline-item--dim' -%}
+    <div class="lt-timeline-item {{ dot_cls }}">
+      <div class="lt-timeline-meta">
+        <strong class="lt-timeline-actor">{{ e.target_name }}</strong>
+        {% if e.target_detail %}<span>· {{ e.target_detail }}</span>{% endif %}
+        <span class="lt-timeline-time event-age" data-ts="{{ e.resolved_at }}">{{ e.resolved_at }}</span>
+      </div>
+      <div class="lt-timeline-body">
+        {{ e.event_type | replace('_', ' ') }}
+        &nbsp;·&nbsp;
+        <span class="lt-badge badge-resolved">{{ e.severity }}</span>
+        &nbsp;·&nbsp; duration
+        <span class="event-duration" data-first="{{ e.first_seen }}" data-resolved="{{ e.resolved_at }}">–</span>
+      </div>
+    </div>
+    {% endfor %}
   </div>
 </section>
 {% endif %}
@@ -529,5 +562,19 @@
   // Re-apply filter after dynamic table updates
   new MutationObserver(applyEventsFilter)
     .observe(document.getElementById('events-table-wrap'), { childList: true, subtree: true });
+
+  // Stat card clicks — filter events table by severity
+  document.querySelectorAll('.lt-stat-card[data-stat-filter]').forEach(card => {
+    card.addEventListener('click', () => {
+      const sev = card.dataset.statFilter;
+      document.querySelectorAll('.sev-pills .pill').forEach(p => p.classList.remove('active'));
+      const matchPill = document.querySelector(`.sev-pills .pill[data-sev="${sev}"]`);
+      if (matchPill) matchPill.classList.add('active');
+      _filterSev = sev;
+      applyEventsFilter();
+      document.getElementById('events-table-wrap')?.scrollIntoView({ behavior: 'smooth', block: 'start' });
+    });
+    card.addEventListener('keydown', e => { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); card.click(); } });
+  });
 </script>
 {% endblock %}