feat: restyle Admin UI with the technical-light design system

Adopt the technical-light design system across the Admin web UI:

- Vendor theme.css + IBM Plex woff2 fonts into wwwroot; include
  theme.css globally after Bootstrap.
- Rebuild MainLayout: top app-bar (brand mark, breadcrumb, connection
  pill) + hairline-ruled side rail with accent-bordered active link.
- Convert all 33 pages to the component catalog — tables to
  panel + data-table (num/mono columns), KPI cards to agg-grid,
  detail blocks to metric-card/kv rows, badges to chips, alerts to
  panel notice, headings to page-title/panel-head, .rise reveals.
- Buttons/forms stay on Bootstrap; theme.css restyles them via
  --bs-* overrides. View-specific layout lives in app.css; all
  colour/type comes from theme.css tokens.

Also fix a pre-existing /fleet 500: the node-state query ordered on
a property of a constructed FleetNodeRow record, which EF Core
cannot translate. Order the join's columns before projecting.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Server/ZB.MOM.WW.OtOpcUa.Admin/Components/Pages/Clusters/NewCluster.razor

@@ -7,7 +7,7 @@
 @inject GenerationService GenerationSvc
 @inject NavigationManager Nav
 
-<h1 class="mb-4">New cluster</h1>
+<h1 class="page-title mb-4">New cluster</h1>
 
 <EditForm Model="_input" OnValidSubmit="CreateAsync" FormName="new-cluster">
     <DataAnnotationsValidator/>
@@ -44,7 +44,7 @@
 
     @if (!string.IsNullOrEmpty(_error))
     {
-        <div class="alert alert-danger mt-3">@_error</div>
+        <section class="panel notice mt-3">@_error</section>
     }
 
     <div class="mt-4">