Apply technical-light design system to the gateway dashboard

Restyles the Blazor dashboard onto a portable token-based theme so it
reads like an instrument panel: warm-paper background, hairline-ruled
panels, IBM Plex type, monospace tabular numerics, and status carried by
colour chips. Vendors theme.css + IBM Plex fonts, rewrites dashboard.css
as a thin token-driven view layer, and swaps the Bootstrap navbar and
status badges for the design-system app bar and chips.

Also includes pending API-key management, Galaxy hierarchy projection,
and constraint-enforcement work with their tests.

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

src/MxGateway.Server/Configuration/EffectiveLdapConfiguration.cs

@@ -0,0 +1,15 @@
+namespace MxGateway.Server.Configuration;
+
+public sealed record EffectiveLdapConfiguration(
+    bool Enabled,
+    string Server,
+    int Port,
+    bool UseTls,
+    bool AllowInsecureLdap,
+    string SearchBase,
+    string ServiceAccountDn,
+    string ServiceAccountPassword,
+    string UserNameAttribute,
+    string DisplayNameAttribute,
+    string GroupAttribute,
+    string RequiredGroup);