docs+ui: backfill XML doc comments and finish dashboard layout pass

Adds missing <summary>/<param> XML docs across 99 server, worker, and test
files so CommentChecker reports zero issues (TreatWarningsAsErrors needs the
analyzer clean). Bundles in WIP dashboard work: NavSection extraction,
MainLayout/site.css/js styling alignment, and DashboardOptions/Auth tweaks.

src/ZB.MOM.WW.MxGateway.Server/Configuration/DashboardOptions.cs

@@ -8,6 +8,19 @@ public sealed class DashboardOptions
     /// <summary>Gets whether anonymous localhost access to dashboard is allowed.</summary>
     public bool AllowAnonymousLocalhost { get; init; } = true;
 
+    /// <summary>
+    /// When true (default), the dashboard auth cookie is restricted to HTTPS
+    /// requests via <see cref="Microsoft.AspNetCore.Http.CookieSecurePolicy.Always"/>.
+    /// Set to false for plain-HTTP dev deployments — the cookie then uses
+    /// <see cref="Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest"/>,
+    /// which still marks it Secure on any HTTPS request but allows it to
+    /// round-trip over HTTP. Browsers silently drop Secure cookies set over
+    /// plain HTTP from non-localhost hosts, so leaving this true breaks
+    /// dashboard login from a remote browser unless the dashboard is served
+    /// over HTTPS.
+    /// </summary>
+    public bool RequireHttpsCookie { get; init; } = true;
+
     /// <summary>Gets the dashboard snapshot update interval in milliseconds.</summary>
     public int SnapshotIntervalMilliseconds { get; init; } = 1_000;