feat: redesign network topology diagram with accurate rack layout

Replace linear Internet→UDM→Agg→PoE→all-hosts chain with accurate topology:
- USW-Aggregation and Pro 24 PoE switch shown side-by-side with horizontal
  10G SFP+ link between them (not in series)
- 5 compute/storage/monitor nodes fanned out under Agg Switch with 10G labels
  and rack unit positions (RU4–12, RU14–17) as sublabels
- large1 shown separately under PoE switch, dashed border = off-rack (table)
- Add device specs as subtitles on all nodes (Dream Machine Pro · RU24, etc.)
- Shorter display names: csg-01 / cs-01 instead of full hostnames
- Live status badges still updated by JS via data-host attributes
- New CSS: .topo-node-sub, .topo-switch-tier, .topo-h-link, .topo-host-tier,
  .topo-host-table (dashed), .topo-badge-unknown

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

static/style.css

@@ -356,6 +356,66 @@ a:hover { text-decoration: underline; text-shadow: var(--glow-amber); }
 
 .topo-status-dot { width:7px; height:7px; border:1px solid var(--text-muted); background:transparent; position:absolute; top:5px; right:5px; }
 
+/* Topology subtitle text */
+.topo-node-sub {
+  font-size: .58em;
+  color: var(--text-muted);
+  letter-spacing: .02em;
+  font-weight: normal;
+}
+
+.topo-badge-unknown { color:var(--text-muted); border-color:var(--border); }
+
+/* Switch tier: two switches with horizontal connector */
+.topo-switch-tier {
+  display: flex;
+  align-items: center;
+  gap: 0;
+}
+
+.topo-h-link {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  padding: 0 8px;
+}
+
+.topo-h-link-line {
+  width: 70px;
+  height: 1px;
+  background: var(--amber);
+  opacity: .5;
+}
+
+.topo-h-link-label {
+  font-size: .52em;
+  color: var(--amber);
+  opacity: .7;
+  margin-top: 3px;
+  letter-spacing: .04em;
+}
+
+/* Host tier: two groups side by side */
+.topo-host-tier {
+  display: flex;
+  justify-content: center;
+  align-items: flex-start;
+  gap: 40px;
+  margin-top: 0;
+}
+
+.topo-host-group { flex-shrink: 0; }
+
+/* PoE host group: offset right to sit below PoE switch */
+.topo-poe-hosts {
+  padding-top: 0;
+}
+
+/* Off-rack node (dashed border) */
+.topo-host-table {
+  border-style: dashed;
+}
+
 /* ── Host cards ───────────────────────────────────────────────────── */
 .host-grid {
   display: grid;