feat(infra): commit live infra-audit/cluster work to reconcile git with prod

This work (network_hosts inventory + infra_audit MCP tool, /api/cluster +
Sacred Valley cluster card, topbar cluster-health pill + SW self-heal) was
built in an earlier session and DEPLOYED to CT 311 as alpha.24–26, but was
never committed to git — prod was running code absent from the repo. Commits
it as-is (already prod-validated) so git matches the live state, and restores
its alpha.24/25/26 CHANGELOG entries. Files are disjoint from the fold-in
work; both now ship together under alpha.27.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/views/cards/cluster.js

@@ -0,0 +1,44 @@
+// public/views/cards/cluster.js — Proxmox cluster health + quorum across nodes.
+import { el, mount } from '../../dom.js';
+import { api } from '../../api.js';
+
+let body, timer;
+
+function nodeRow(n, master) {
+  const tags = [];
+  if (n.local) tags.push('local');
+  if (master === n.name) tags.push('master');
+  return el('div', { class: 'sv-row status-' + (n.online ? 'ok' : 'down') },
+    el('span', { class: 'k' }, el('span', { class: 'dot' }), n.name),
+    el('span', {}, (n.online ? 'online' : 'OFFLINE') + (tags.length ? ' · ' + tags.join(' · ') : '')));
+}
+
+async function load() {
+  if (!body) return;
+  try {
+    const c = await api.get('/api/cluster');
+    if (c.error) { mount(body, el('span', { class: 'muted' }, 'Cluster: ' + c.error)); return; }
+    const haIssues = c.ha?.services_error || 0;
+    const rows = el('div', { class: 'sv-cluster' },
+      el('div', { class: 'sv-row' },
+        el('span', { class: 'k' }, 'Quorum'),
+        el('span', { class: 'cl-badge ' + (c.quorate ? 'ok' : 'bad') }, c.quorate ? 'QUORATE' : 'NO QUORUM')),
+      el('div', { class: 'sv-row' },
+        el('span', { class: 'k' }, 'Nodes'),
+        el('span', { class: c.nodes_online < c.nodes_total ? 'warn' : '' }, `${c.nodes_online}/${c.nodes_total} online`)),
+      ...(c.nodes || []).map(n => nodeRow(n, c.ha?.master)),
+      el('div', { class: 'sv-row' },
+        el('span', { class: 'k' }, 'HA services'),
+        el('span', { class: haIssues ? 'warn' : '' },
+          haIssues ? `${c.ha.services_total} · ${haIssues} ⚠` : `${c.ha?.services_total ?? 0} · ok`))
+    );
+    mount(body, rows);
+  } catch { mount(body, el('span', { class: 'muted' }, 'Cluster unavailable')); }
+}
+
+export default {
+  id: 'cluster', title: 'Cluster · HZ', size: 'm',
+  mount(e) { body = e; load(); },
+  start() { timer = setInterval(load, 30000); },
+  stop() { clearInterval(timer); body = null; }
+};