Enhance app management with 'IsRecommended' feature

- Added 'IsRecommended' property to app-related data models, allowing apps to be marked as recommended.
- Updated API endpoints for creating and updating apps to include 'IsRecommended' in request bodies.
- Modified database schema to accommodate the new 'IsRecommended' field.
- Enhanced frontend components to display recommended apps with a star icon and updated forms to manage this property.
- Improved sorting logic in app listings to prioritize recommended apps.
- Updated documentation to reflect changes in API and data models.

backend/src/PnvPanel.Api/Endpoints/AdminAppEndpoints.cs

@@ -53,7 +53,8 @@ public static class AdminAppEndpoints
             body.Description,
             body.IconUrl,
             body.SortOrder,
-            body.IsEnabled
+            body.IsEnabled,
+            body.IsRecommended
         );
         var result = await sender.Send(command, cancellationToken);
         return result.ToHttpResult();
@@ -77,5 +78,6 @@ public sealed record UpdateAppBody(
     string? Description,
     string? IconUrl,
     int SortOrder,
-    bool IsEnabled
+    bool IsEnabled,
+    bool IsRecommended
 );