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.Application/Apps/ClientAppDto.cs

@@ -7,9 +7,17 @@ public sealed record ClientAppDto(
     string Name,
     string DownloadUrl,
     string? Description,
-    string? IconUrl
+    string? IconUrl,
+    bool IsRecommended
 )
 {
     public static ClientAppDto FromDomain(ClientApp app) =>
-        new(app.Id, app.Name, app.DownloadUrl.ToString(), app.Description, app.IconUrl);
+        new(
+            app.Id,
+            app.Name,
+            app.DownloadUrl.ToString(),
+            app.Description,
+            app.IconUrl,
+            app.IsRecommended
+        );
 }

backend/src/PnvPanel.Application/Apps/ListAppsQueryHandler.cs

@@ -20,7 +20,8 @@ public sealed class ListAppsQueryHandler(IAppDbContext dbContext)
         var apps = await dbContext
             .ClientApps.AsNoTracking()
             .Where(a => a.IsEnabled)
-            .OrderBy(a => a.SortOrder)
+            .OrderByDescending(a => a.IsRecommended)
+            .ThenBy(a => a.SortOrder)
             .ToListAsync(cancellationToken);
 
         var grouped = apps.GroupBy(a => a.OperatingSystem)