Redesign The Hub web UI: softer dark theme, sidebar nav, status widgets

Apply the approved "The Hub" redesign to the web admin while keeping every
existing mechanic intact (polling, service-detail modals, Matrix and system
password management, NWC wallet manager, update/rebuild/backup/security/
reboot flows, feature manager, onboarding, role handling).

Layout (templates/index.html):
- Old header bar + IP bar replaced by a sidebar + topbar app shell.
  Sidebar carries the brand (The Hub / Sovran_SystemsOS version), category
  navigation with live counts, the System actions (Update System, Tech
  Support, Manual Backup, Security, node-only Upgrade), Feature Manager /
  Preferences, and the role badge.
- Topbar carries the page title, a service search box, the LAN | WAN
  network chip (external IP always visible, one line), Reboot and Sign Out.
- New widgets row: Systems Operational summary (opens the new Systems
  Operational modal) and Bitcoin Core sync progress with block/ETA.
- New Systems Operational modal: service counts, router port-forwarding
  steps (80/443 to this machine's LAN IP), the live domain diagnostics
  checklist, and which services use those ports.

New static/js/dashboard.js (namespaced IIFE, no new globals) renders the
nav, search filtering, widgets, and the Systems Operational modal; it is
driven by the existing /api/services payloads via a
window.dashboardServicesUpdated() hook called from buildTiles/updateTiles.

Visual design (static/css/*):
- New token set (softer dark surfaces, lifted contrast, Sovran green
  reserved for status and actions) with legacy variable names aliased so
  every secondary sheet re-skins automatically.
- Tiles, dialogs, buttons, inputs, toggles, tables, forms, overlays and
  the login page restyled to the GNOME/libadwaita-flavored surfaces:
  20px cards, 26px dialogs, pill buttons, libadwaita switches, mono value
  pills with Copy buttons, consistent modal anatomy.
- Inline SVG symbol set for chrome/nav icons (monochrome, currentColor);
  service icons still load from /static/icons/*.svg as before.
- Sidebar system buttons now use vector glyphs instead of emoji.

Behavioral details:
- Service detail modal header gains a status pill next to the version
  chip; credentials render with pre-wrap for multiline values.
- First-login security banner now renders as a card inside the content
  area instead of a full-width strip above the app.
- Search + category filtering hide/show sections and tiles without
  touching the polling or update logic.

Onboarding and login pages rebranded to "The Hub" with aligned palette.

app/sovran_systemsos_web/static/css/domain-setup.css

@@ -18,7 +18,7 @@ domain-field-label {
 
 domain-field-input {
   width: 100%;
-  background-color: #0c0f0e;
+  background-color: var(--inset);
   color: var(--text-primary);
   border: 1px solid var(--border-color);
   border-radius: 8px;
@@ -75,7 +75,7 @@ domain-field-actions {
 
 .domain-field-input {
   width: 100%;
-  background-color: #0c0f0e;
+  background-color: var(--inset);
   color: var(--text-primary);
   border: 1px solid var(--border-color);
   border-radius: 8px;
@@ -198,21 +198,21 @@ domain-field-actions {
 }
 
 .port-proto-badge--tcp {
-  color: #6dbf8b;
-  background: rgba(109, 191, 139, 0.12);
-  border: 1px solid rgba(109, 191, 139, 0.4);
+  color: var(--accent);
+  background: rgba(66, 243, 154, 0.12);
+  border: 1px solid rgba(66, 243, 154, 0.4);
 }
 
 .port-proto-badge--udp {
-  color: #6aa9e0;
+  color: var(--blue);
   background: rgba(106, 169, 224, 0.12);
   border: 1px solid rgba(106, 169, 224, 0.4);
 }
 
 .port-proto-badge--both {
-  color: #e5a50a;
-  background: rgba(229, 165, 10, 0.12);
-  border: 1px solid rgba(229, 165, 10, 0.45);
+  color: var(--amber);
+  background: rgba(233, 182, 74, 0.12);
+  border: 1px solid rgba(233, 182, 74, 0.45);
 }
 
 .port-proto-note {
@@ -230,7 +230,7 @@ domain-field-actions {
   margin-bottom: 14px;
   padding: 10px 14px;
   background: rgba(255, 180, 0, 0.10);
-  border: 1px solid var(--warning-color, #f59e0b);
+  border: 1px solid var(--warning-color, var(--amber));
   border-radius: 8px;
   font-size: 0.88rem;
   line-height: 1.6;