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/Layout/MainLayout.razor

@@ -1,38 +1,58 @@
 @inherits LayoutComponentBase
 
-<div class="d-flex" style="min-height: 100vh;">
-    <nav class="bg-dark text-light p-3" style="width: 220px;">
-        <h5 class="mb-4">OtOpcUa Admin</h5>
-        <ul class="nav flex-column">
-            <li class="nav-item"><a class="nav-link text-light" href="/">Overview</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/fleet">Fleet status</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/hosts">Host status</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/clusters">Clusters</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/reservations">Reservations</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/certificates">Certificates</a></li>
-            <li class="nav-item"><a class="nav-link text-light" href="/role-grants">Role grants</a></li>
-        </ul>
+<header class="app-bar">
+    <span class="brand"><span class="mark">&#9646;</span> OtOpcUa</span>
+    <span class="crumb">&rsaquo;</span>
+    <span class="crumb">admin console</span>
+    <span class="spacer"></span>
+    <AuthorizeView>
+        <Authorized>
+            <span class="meta">@context.User.Identity?.Name</span>
+            <span class="conn-pill" data-state="connected">
+                <span class="dot"></span><span>signed in</span>
+            </span>
+        </Authorized>
+        <NotAuthorized>
+            <span class="conn-pill" data-state="disconnected">
+                <span class="dot"></span><span>signed out</span>
+            </span>
+        </NotAuthorized>
+    </AuthorizeView>
+</header>
 
-        <div class="mt-5">
+<div class="app-shell">
+    <nav class="side-rail">
+        <div class="rail-eyebrow">Navigation</div>
+        <NavLink class="rail-link" href="/" Match="NavLinkMatch.All">Overview</NavLink>
+        <NavLink class="rail-link" href="/fleet" Match="NavLinkMatch.Prefix">Fleet status</NavLink>
+        <NavLink class="rail-link" href="/hosts" Match="NavLinkMatch.Prefix">Host status</NavLink>
+        <NavLink class="rail-link" href="/clusters" Match="NavLinkMatch.Prefix">Clusters</NavLink>
+        <NavLink class="rail-link" href="/reservations" Match="NavLinkMatch.Prefix">Reservations</NavLink>
+        <NavLink class="rail-link" href="/certificates" Match="NavLinkMatch.Prefix">Certificates</NavLink>
+        <NavLink class="rail-link" href="/role-grants" Match="NavLinkMatch.Prefix">Role grants</NavLink>
+
+        <div class="rail-foot">
             <AuthorizeView>
                 <Authorized>
-                    <div class="small text-light">
-                        Signed in as <a class="text-light" href="/account"><strong>@context.User.Identity?.Name</strong></a>
-                    </div>
-                    <div class="small text-muted">
-                        @string.Join(", ", context.User.Claims.Where(c => c.Type.EndsWith("/role")).Select(c => c.Value))
+                    <div class="rail-eyebrow">Session</div>
+                    <a class="rail-user" href="/account">@context.User.Identity?.Name</a>
+                    <div class="rail-roles">
+                        @string.Join(", ", context.User.Claims
+                            .Where(c => c.Type.EndsWith("/role")).Select(c => c.Value))
                     </div>
                     <form method="post" action="/auth/logout">
-                        <button class="btn btn-sm btn-outline-light mt-2" type="submit">Sign out</button>
+                        <button class="rail-btn" type="submit">Sign out</button>
                     </form>
                 </Authorized>
                 <NotAuthorized>
-                    <a class="btn btn-sm btn-outline-light" href="/login">Sign in</a>
+                    <div class="rail-eyebrow">Session</div>
+                    <a class="rail-btn" href="/login">Sign in</a>
                 </NotAuthorized>
             </AuthorizeView>
         </div>
     </nav>
-    <main class="flex-grow-1 p-4">
+
+    <main class="page">
         @Body
     </main>
 </div>