Centralize the home slug check on Page, case-insensitively

Elternbeirat.Web/Features/Layout/NavBuilder.cs

@@ -17,7 +17,9 @@ public static class NavBuilder
     public static IReadOnlyList<NavLinkItem> Footer(IReadOnlyList<Page> pages) =>
         Build(pages, "footer");
 
-    private static List<NavLinkItem> Build(IReadOnlyList<Page> pages, string location) =>
+    private static List<NavLinkItem> Build(
+        IReadOnlyList<Page> pages,
+        string location) =>
         [.. pages
             .Where(page => string.Equals(page.Location, location, StringComparison.Ordinal))
             .OrderBy(page => page.Order)
@@ -27,5 +29,5 @@ public static class NavBuilder
     // reached at "/{slug}", where either a literal route or the catch-all content
     // page renders it.
     private static string HrefFor(string slug) =>
-        string.Equals(slug, "home", StringComparison.Ordinal) ? "/" : $"/{slug}";
+        Page.IsHomeSlug(slug) ? "/" : $"/{slug}";
 }