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/DashboardGalaxyProjector.cs

@@ -5,6 +5,8 @@ namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 /// <summary>Projects the precomputed Galaxy cache dashboard summary.</summary>
 internal static class DashboardGalaxyProjector
 {
+    /// <summary>Projects the cache entry to a dashboard Galaxy summary.</summary>
+    /// <param name="entry">The Galaxy hierarchy cache entry.</param>
     public static DashboardGalaxySummary Project(GalaxyHierarchyCacheEntry entry)
     {
         return entry.DashboardSummary;