feat(centralui): rebrand web UI to ScadaBridge + technical-light theme

Rename the user-facing product name from ScadaLink to ScadaBridge across
the six display strings (browser title, sidebar brand, login + not-authorized
headings, dashboard welcome/subtitle). Namespaces, assemblies, config keys,
and _content/ScadaLink.CentralUI asset routes are unchanged.

Apply the technical-light design system: vendor theme.css + IBM Plex fonts
into the CentralUI RCL, include theme.css globally (after Bootstrap so its
--bs-* token overrides win), and restyle the layout chrome to a light
sidebar — white surface, hairline rules, ink text, accent-blue active item,
the brand accent mark. Page markup stays Bootstrap and inherits the warm
paper background, Plex type, accent, and hairline borders via the tokens.

Tests: build 0 warnings; bUnit 542 passed; Playwright 64 passed.

src/ScadaLink.CentralUI/Components/Pages/Login.razor

@@ -6,7 +6,7 @@
 <div class="d-flex align-items-center justify-content-center min-vh-100">
     <div class="card shadow-sm" style="max-width: 400px; width: 100%;">
         <div class="card-body p-4">
-            <h4 class="card-title mb-4 text-center">ScadaLink</h4>
+            <h4 class="card-title mb-4 text-center">ScadaBridge</h4>
 
             @if (!string.IsNullOrEmpty(ErrorMessage))
             {