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.Infrastructure/Persistence/Migrations/AppDbContextModelSnapshot.cs

@@ -185,6 +185,9 @@ namespace PnvPanel.Infrastructure.Persistence.Migrations
                     b.Property<bool>("IsEnabled")
                         .HasColumnType("boolean");
 
+                    b.Property<bool>("IsRecommended")
+                        .HasColumnType("boolean");
+
                     b.Property<string>("Name")
                         .IsRequired()
                         .HasMaxLength(100)