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);

src/MxGateway.Server/Configuration/LdapOptions.cs

@@ -0,0 +1,28 @@
+namespace MxGateway.Server.Configuration;
+
+public sealed class LdapOptions
+{
+    public bool Enabled { get; init; } = true;
+
+    public string Server { get; init; } = "localhost";
+
+    public int Port { get; init; } = 3893;
+
+    public bool UseTls { get; init; }
+
+    public bool AllowInsecureLdap { get; init; } = true;
+
+    public string SearchBase { get; init; } = "dc=lmxopcua,dc=local";
+
+    public string ServiceAccountDn { get; init; } = "cn=serviceaccount,dc=lmxopcua,dc=local";
+
+    public string ServiceAccountPassword { get; init; } = "serviceaccount123";
+
+    public string UserNameAttribute { get; init; } = "cn";
+
+    public string DisplayNameAttribute { get; init; } = "cn";
+
+    public string GroupAttribute { get; init; } = "memberOf";
+
+    public string RequiredGroup { get; init; } = "GwAdmin";
+}