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/tests/PnvPanel.Domain.Tests/Apps/ClientAppTests.cs

@@ -14,13 +14,15 @@ public class ClientAppTests
             OsPlatform.Android,
             "desc",
             null,
-            1
+            1,
+            isRecommended: false
         );
 
         Assert.Equal("v2rayNG", app.Name);
         Assert.Equal(OsPlatform.Android, app.OperatingSystem);
         Assert.True(app.IsEnabled);
         Assert.Equal(1, app.SortOrder);
+        Assert.False(app.IsRecommended);
     }
 
     [Fact]
@@ -32,7 +34,8 @@ public class ClientAppTests
             OsPlatform.IOS,
             "old",
             "old-icon",
-            1
+            1,
+            isRecommended: false
         );
 
         app.Update(
@@ -42,7 +45,8 @@ public class ClientAppTests
             "new",
             "new-icon",
             2,
-            isEnabled: false
+            isEnabled: false,
+            isRecommended: true
         );
 
         Assert.Equal("New", app.Name);
@@ -52,5 +56,6 @@ public class ClientAppTests
         Assert.Equal("new-icon", app.IconUrl);
         Assert.Equal(2, app.SortOrder);
         Assert.False(app.IsEnabled);
+        Assert.True(app.IsRecommended);
     }
 }