[Fix] Search navigation routing API models to blank page

AIDevGallery/MainWindow.xaml.cs

@@ -132,9 +132,23 @@ public void NavigateToPage(object? obj)
         {
             NavigateToApiOrModelPage(modelTypes[0]);
         }
-        else if (obj is ModelDetails)
-        {
-            Navigate("Models", obj);
+        else if (obj is ModelDetails modelDetails)
+        {
+            // ModelDetails only contains an Id, not a direct ModelType reference.
+            // We need to look up the ModelType to determine if this should route to:
+            // - APISelectionPage (for WCRAPIs and children)
+            // - ModelSelectionPage (for all other models)
+            // This enables intelligent routing from search results and external navigation.
+            var modelTypeList = App.FindSampleItemById(modelDetails.Id);
+            if (modelTypeList.Count > 0)
+            {
+                NavigateToApiOrModelPage(modelTypeList[0]);
+            }
+            else
+            {
+                // Fallback: If ID lookup fails (e.g., user-added models), default to Models page
+                Navigate("Models", obj);
+            }
         }
         else if (obj is SampleNavigationArgs)
         {
@@ -198,8 +212,36 @@ private void Navigate(Type page, object? param = null)
 
             if (page == typeof(APISelectionPage) && NavFrame.Content is APISelectionPage apiPage && param != null)
             {
-                // No need to navigate to the APISelectionPage again, we just want to navigate to the right subpage
-                apiPage.SetSelectedApiInMenu((ModelType)param);
+                // Optimize: Avoid re-navigating if already on APISelectionPage
+                // Just update the selected item in the navigation menu
+                if (param is ModelType modelType)
+                {
+                    apiPage.SetSelectedApiInMenu(modelType);
+                }
+                else
+                {
+                    // ModelDetails needs full navigation as APISelectionPage.OnNavigatedTo handles the lookup
+                    // Unknown parameter type - perform full navigation to be safe
+                    NavFrame.Navigate(page, param);
+                }
+            }
+            else if (page == typeof(ModelSelectionPage) && NavFrame.Content is ModelSelectionPage modelPage && param != null)
+            {
+                // Optimize: Avoid re-navigating if already on ModelSelectionPage
+                // Use the same pattern as APISelectionPage
+                if (param is ModelType modelType)
+                {
+                    modelPage.SetSelectedModelInMenu(modelType);
+                }
+                else if (param is List<ModelType> modelTypes && modelTypes.Count > 0)
+                {
+                    modelPage.SetSelectedModelInMenu(modelTypes[0]);
+                }
+                else
+                {
+                    // For other parameter types (ModelDetails, string, MRU), perform full navigation
+                    NavFrame.Navigate(page, param);
+                }
             }
             else if (page == typeof(ScenarioSelectionPage) && NavFrame.Content is ScenarioSelectionPage scenarioPage && param != null)
             {
@@ -258,7 +300,7 @@ public void Navigate(SearchResult result)
         }
         else if (result.Tag is ModelType modelType)
         {
-            Navigate("models", modelType);
+            NavigateToApiOrModelPage(modelType);
         }
     }
 

AIDevGallery/Pages/APIs/APIOverview.xaml.cs

@@ -45,7 +45,7 @@ private void APIViewer_ItemInvoked(ItemsView sender, ItemsViewItemInvokedEventAr
                 {
                     if (apiDefinition == api)
                     {
-                        App.MainWindow.Navigate("apis", item);
+                        App.MainWindow.NavigateToPage(item);
                     }
                 }
             }

AIDevGallery/Pages/Models/ModelSelectionPage.xaml.cs

@@ -273,6 +273,19 @@ private void NavView_SelectionChanged(NavigationView sender, NavigationViewSelec
         }
     }
 
+    /// <summary>
+    /// Public method to update the selected model in the navigation menu without re-navigating.
+    /// This mirrors the behavior of APISelectionPage.SetSelectedApiInMenu for consistency.
+    /// </summary>
+    public void SetSelectedModelInMenu(ModelType selectedType)
+    {
+        var modelTypes = new List<ModelType> { selectedType };
+        foreach (NavigationViewItem item in NavView.MenuItems)
+        {
+            SetSelectedSampleInMenu(item, modelTypes, null);
+        }
+    }
+
     private void SetSelectedSampleInMenu(NavigationViewItem item, List<ModelType>? selectedSample = null, ModelDetails? details = null)
     {
         if (selectedSample == null && details == null)