Serve the home nav link from PocketBase, not a hard-coded copy

Elternbeirat.Web/Features/Layout/NavBuilder.cs

@@ -3,9 +3,9 @@ using Elternbeirat.Contracts;
 namespace Elternbeirat.Web.Features.Layout;
 
 /// <summary>
-/// Builds the header and footer navigation from the public pages. Pages carry a
-/// <see cref="Page.Location"/> ("header"/"footer"/"") and an <see cref="Page.Order"/>;
-/// pages without a location are sub-pages and never appear in a menu.
+/// Builds the header and footer navigation from the public pages. Every page
+/// carries a required <see cref="Page.Location"/> ("header" or "footer") and an
+/// <see cref="Page.Order"/>; this splits them into the two menus, each ordered.
 /// </summary>
 public static class NavBuilder
 {