Fix hx-select-oob for nav crosslinks

Author: theletterf

src/Elastic.ApiExplorer/Landing/LandingNavigationItem.cs

@@ -33,6 +33,7 @@ public class LandingNavigationItem : IApiGroupingNavigationItem<ApiLanding, INav
 	public IReadOnlyCollection<INavigationItem> NavigationItems { get; set; } = [];
 	public INodeNavigationItem<INavigationModel, INavigationItem>? Parent { get; set; }
 	public int NavigationIndex { get; set; }
+	public bool IsCrossLink => false; // API landing items are never cross-links
 	public string Url { get; }
 	public bool Hidden => false;
 
@@ -83,6 +84,7 @@ public abstract class ApiGroupingNavigationItem<TGroupingModel, TNavigationItem>
 	public bool Hidden => false;
 	/// <inheritdoc />
 	public int NavigationIndex { get; set; }
+	public bool IsCrossLink => false; // API grouping items are never cross-links
 
 	/// <inheritdoc />
 	public int Depth => 0;
@@ -141,6 +143,7 @@ public class EndpointNavigationItem(ApiEndpoint endpoint, IRootNavigationItem<IA
 
 	/// <inheritdoc />
 	public int NavigationIndex { get; set; }
+	public bool IsCrossLink => false; // API endpoint items are never cross-links
 
 	/// <inheritdoc />
 	public int Depth => 0;

src/Elastic.ApiExplorer/Operations/OperationNavigationItem.cs

@@ -70,5 +70,6 @@ IApiGroupingNavigationItem<IApiGroupingModel, INavigationItem> parent
 	public INodeNavigationItem<INavigationModel, INavigationItem>? Parent { get; set; }
 
 	public int NavigationIndex { get; set; }
+	public bool IsCrossLink => false; // API operations are never cross-links
 
 }

src/Elastic.Documentation.Site/Navigation/INavigationItem.cs

@@ -34,6 +34,9 @@ public interface INavigationItem
 	bool Hidden { get; }
 
 	int NavigationIndex { get; set; }
+
+	/// Gets whether this navigation item is a cross-link to another repository.
+	bool IsCrossLink { get; }
 }
 
 /// Represents a leaf node in the navigation tree with associated model data.

src/Elastic.Documentation.Site/Navigation/_TocTreeNav.cshtml

@@ -79,10 +79,11 @@
 	}
 	else if (item is ILeafNavigationItem<INavigationModel> leaf)
 	{
+		var hasSameTopLevelGroup = !leaf.IsCrossLink && (Model.IsPrimaryNavEnabled && leaf.NavigationRoot.Id == Model.RootNavigationId || true);
 		<li class="flex group/li pr-8 @(isTopLevel ? "font-semibold mt-6" : "mt-4")">
 			<a
 				href="@leaf.Url"
-				@Htmx.GetNavHxAttributes(Model.IsPrimaryNavEnabled && leaf.NavigationRoot.Id == Model.RootNavigationId || true)
+				@Htmx.GetNavHxAttributes(hasSameTopLevelGroup)
 				class="sidebar-link grow group-[.current]/li:text-blue-elastic!"
 			>
 				@leaf.NavigationTitle

src/Elastic.Markdown/IO/Navigation/CrossLinkNavigationItem.cs

@@ -63,5 +63,6 @@ private string GetNavigationTitleFromUrl(string url)
 	public string Url => ResolvedUrl ?? _url; public string NavigationTitle { get; }
 	public int NavigationIndex { get; set; }
 	public bool Hidden { get; }
+	public bool IsCrossLink => true; // This is always a cross-link
 	public INavigationModel Model => null!; // Cross-link has no local model
 }

src/Elastic.Markdown/IO/Navigation/DocumentationGroup.cs

@@ -32,6 +32,8 @@ public class DocumentationGroup : INodeNavigationItem<MarkdownFile, INavigationI
 
 	public int NavigationIndex { get; set; }
 
+	public bool IsCrossLink => false; // Documentation groups are never cross-links
+
 	private IReadOnlyCollection<MarkdownFile> FilesInOrder { get; }
 
 	private IReadOnlyCollection<DocumentationGroup> GroupsInOrder { get; }

src/Elastic.Markdown/IO/Navigation/FileNavigationItem.cs

@@ -16,4 +16,5 @@ public record FileNavigationItem(MarkdownFile Model, DocumentationGroup Group, b
 	public string Url => Model.Url;
 	public string NavigationTitle => Model.NavigationTitle;
 	public int NavigationIndex { get; set; }
+	public bool IsCrossLink => false; // File navigation items are never cross-links
 }