feat(web): dashboard redesign — Gitea palette, health panels, VM/audit enrichment (stages A–C)

Stage A: swap CSS tokens to the real Gitea dark palette (accent blue #4183c4); add Jinja formatting filters (humanbytes/duration/relative_time/localtime/shorten_path/thousands), a health status-header, and an inline SVG icon sprite; fix two UI bugs — unthemed action pages (htmx swap into #action-slot with a full-page HX-Request fallback) and polling wiping form input (hx-preserve).

Stage B: four read-only panels that degrade to notices (never 500) — host resources (/proc, two-sample CPU%), VMware module health, template inventory (.vmem warn + last backup), and a path-contained file browser; backup card becomes a validated template dropdown; expensive dir-size walk is TTL-cached. Adds operations/inventory.py plus host_resources()/vmware_module_health() in operations/host.py.

Stage C: parse_clone_name() adds a Job column (job_id + started) to the VM table; nav gains a Gitea link-out derived from the OIDC issuer origin (no fabricated run URLs); audit page gets action icons, relative time, and a client-side filter.

Gates: 989 tests pass, coverage 94.12%, ruff + mypy --strict clean. Stage D (service management) intentionally deferred.

src/ci_orchestrator/web/templates/partials/host.html

@@ -1,6 +1,6 @@
 <div class="contents" id="host-partial" hx-get="/host" hx-trigger="every 5s" hx-swap="outerHTML">
   <section class="card" id="disk-card">
-    <h2>Disk</h2>
+    <h2><svg class="icon" aria-hidden="true"><use href="#i-disk"></use></svg>Disk</h2>
     {% if disk %}
     <dl>
       <dt>Path</dt><dd><code>{{ disk.path }}</code></dd>
@@ -14,7 +14,7 @@
   </section>
 
   <section class="card" id="runner-card">
-    <h2>Runners</h2>
+    <h2><svg class="icon" aria-hidden="true"><use href="#i-gear"></use></svg>Runners</h2>
     {% if runners %}
     <div class="table-wrap">
       <table>
@@ -48,11 +48,17 @@
   </section>
 
   <section class="card" id="backup-card">
-    <h2>Template backup</h2>
-    <form method="post" action="/host/backup" id="host-backup-form" aria-label="Backup template">
+    <h2><svg class="icon" aria-hidden="true"><use href="#i-box"></use></svg>Template backup</h2>
+    <p class="field-hint">7z archive of the template dir under &lt;root&gt;/backups</p>
+    <form method="post" action="/host/backup" id="host-backup-form" aria-label="Backup template"
+          hx-post="/host/backup" hx-target="#action-slot" hx-swap="innerHTML">
       <input type="hidden" name="csrf" value="{{ csrf_token }}">
       <label for="host-backup-template">Template</label>
-      <input type="text" id="host-backup-template" name="template" required>
+      <select id="host-backup-template" name="template" required hx-preserve="true">
+        {% for name in template_names %}
+        <option value="{{ name }}">{{ name }}</option>
+        {% endfor %}
+      </select>
       <button type="submit" class="btn btn-danger" aria-label="Backup template">Backup template</button>
     </form>
   </section>