Refactor project files for improved readability and structure

- Cleaned up whitespace in Directory.Build.props and Directory.Packages.props for consistency.
- Reformatted project file references in PnvPanel.Api.csproj for better clarity.
- Enhanced code readability in various endpoint files by adjusting line breaks and indentation.
- Standardized method signatures and improved formatting in ResultExtensions and multiple endpoint classes for better maintainability.

backend/src/PnvPanel.Application/Admin/Stats/GetStatsQueryHandler.cs

@@ -11,27 +11,47 @@ namespace PnvPanel.Application.Admin.Stats;
 public sealed class GetStatsQueryHandler(IAppDbContext dbContext, IIdentityService identityService)
     : IQueryHandler<GetStatsQuery, Result<StatsDto>>
 {
-    public async Task<Result<StatsDto>> Handle(GetStatsQuery query, CancellationToken cancellationToken)
+    public async Task<Result<StatsDto>> Handle(
+        GetStatsQuery query,
+        CancellationToken cancellationToken
+    )
     {
         var userStats = await identityService.GetUserStatsAsync(cancellationToken);
 
-        var pendingActivations = await dbContext.ActivationRequests
-            .CountAsync(r => r.Status == ActivationStatus.Pending, cancellationToken);
+        var pendingActivations = await dbContext.ActivationRequests.CountAsync(
+            r => r.Status == ActivationStatus.Pending,
+            cancellationToken
+        );
 
         var totalNodes = await dbContext.Nodes.CountAsync(cancellationToken);
-        var onlineNodes = await dbContext.Nodes.CountAsync(n => n.Status == NodeStatus.Online, cancellationToken);
+        var onlineNodes = await dbContext.Nodes.CountAsync(
+            n => n.Status == NodeStatus.Online,
+            cancellationToken
+        );
 
         var totalConfigs = await dbContext.VpnConfigs.CountAsync(cancellationToken);
-        var activeConfigs = await dbContext.VpnConfigs.CountAsync(c => c.Status == ConfigStatus.Active, cancellationToken);
+        var activeConfigs = await dbContext.VpnConfigs.CountAsync(
+            c => c.Status == ConfigStatus.Active,
+            cancellationToken
+        );
 
-        var trafficTotals = await dbContext.VpnConfigs
-            .GroupBy(_ => 1)
+        var trafficTotals = await dbContext
+            .VpnConfigs.GroupBy(_ => 1)
             .Select(g => new { Up = g.Sum(c => c.UsedUpBytes), Down = g.Sum(c => c.UsedDownBytes) })
             .FirstOrDefaultAsync(cancellationToken);
 
-        return Result.Success(new StatsDto(
-            userStats.Total, userStats.Activated, pendingActivations,
-            totalNodes, onlineNodes, totalConfigs, activeConfigs,
-            trafficTotals?.Up ?? 0, trafficTotals?.Down ?? 0));
+        return Result.Success(
+            new StatsDto(
+                userStats.Total,
+                userStats.Activated,
+                pendingActivations,
+                totalNodes,
+                onlineNodes,
+                totalConfigs,
+                activeConfigs,
+                trafficTotals?.Up ?? 0,
+                trafficTotals?.Down ?? 0
+            )
+        );
     }
 }