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/Galaxy/GalaxyHierarchyIndex.cs

@@ -14,17 +14,24 @@ public sealed class GalaxyHierarchyIndex
         TagsByAddress = tagsByAddress;
     }
 
+    /// <summary>Gets an empty Galaxy hierarchy index.</summary>
     public static GalaxyHierarchyIndex Empty { get; } = new(
         Array.Empty<GalaxyObjectView>(),
         new Dictionary<int, GalaxyObjectView>(),
         new Dictionary<string, GalaxyTagLookup>(StringComparer.OrdinalIgnoreCase));
 
+    /// <summary>Gets the object views.</summary>
     public IReadOnlyList<GalaxyObjectView> ObjectViews { get; }
 
+    /// <summary>Gets the object views indexed by GUID.</summary>
     public IReadOnlyDictionary<int, GalaxyObjectView> ObjectViewsById { get; }
 
+    /// <summary>Gets tags indexed by address.</summary>
     public IReadOnlyDictionary<string, GalaxyTagLookup> TagsByAddress { get; }
 
+    /// <summary>Builds a Galaxy hierarchy index from the given objects.</summary>
+    /// <param name="objects">The Galaxy objects to index.</param>
+    /// <returns>A new Galaxy hierarchy index.</returns>
     public static GalaxyHierarchyIndex Build(IReadOnlyList<GalaxyObject> objects)
     {
         if (objects.Count == 0)