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/Dashboard/IDashboardApiKeyManagementService.cs

@@ -4,23 +4,46 @@ namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 
 public interface IDashboardApiKeyManagementService
 {
+    /// <summary>Determines whether the user can manage API keys.</summary>
+    /// <param name="user">The user principal.</param>
+    /// <returns>True if the user can manage keys; otherwise false.</returns>
     bool CanManage(ClaimsPrincipal user);
 
+    /// <summary>Creates a new API key.</summary>
+    /// <param name="user">The user principal.</param>
+    /// <param name="request">The key creation request details.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The creation result.</returns>
     Task<DashboardApiKeyManagementResult> CreateAsync(
         ClaimsPrincipal user,
         DashboardApiKeyManagementRequest request,
         CancellationToken cancellationToken);
 
+    /// <summary>Revokes an existing API key.</summary>
+    /// <param name="user">The user principal.</param>
+    /// <param name="keyId">The key identifier to revoke.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The revocation result.</returns>
     Task<DashboardApiKeyManagementResult> RevokeAsync(
         ClaimsPrincipal user,
         string keyId,
         CancellationToken cancellationToken);
 
+    /// <summary>Rotates an existing API key.</summary>
+    /// <param name="user">The user principal.</param>
+    /// <param name="keyId">The key identifier to rotate.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The rotation result.</returns>
     Task<DashboardApiKeyManagementResult> RotateAsync(
         ClaimsPrincipal user,
         string keyId,
         CancellationToken cancellationToken);
 
+    /// <summary>Deletes an API key.</summary>
+    /// <param name="user">The user principal.</param>
+    /// <param name="keyId">The key identifier to delete.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The deletion result.</returns>
     Task<DashboardApiKeyManagementResult> DeleteAsync(
         ClaimsPrincipal user,
         string keyId,