Implement rate limiting and enhance authentication flow

- Added rate limiting configuration for authentication endpoints, allowing customizable request limits via environment variables.
- Updated authentication flow to utilize HttpRequest for cookie management, ensuring secure handling of refresh tokens.
- Introduced a new endpoint to retrieve user subscription details.
- Enhanced the handling of Telegram bot token validation to prevent errors with empty tokens.
- Updated the application to serialize enums as strings for better documentation and compatibility with TypeScript.
- Improved test coverage for new features and adjustments in command handlers.

backend/tests/PnvPanel.IntegrationTests/Configs/ConfigQuotaTests.cs

@@ -15,12 +15,14 @@ public class ConfigQuotaTests(PnvPanelWebApplicationFactory factory)
 
     private sealed record NodeResponse(Guid Id, string Name);
 
-    private sealed record SyncNodeResponse(int InboundsSynced, int Status);
+    private sealed record SyncNodeResponse(int InboundsSynced, string Status);
 
-    private sealed record InboundResponse(Guid Id, Guid NodeId, string RemoteInboundId, int Protocol, string Remark, int Port, bool IsPublished);
+    private sealed record InboundResponse(Guid Id, Guid NodeId, string RemoteInboundId, string Protocol, string Remark, int Port, bool IsPublished);
 
     private sealed record ActivationRequestResponse(Guid Id, string? Comment, DateTimeOffset CreatedAt);
 
+    private sealed record MyConfigsResponse(List<object> Configs, int MaxConfigs);
+
     /// <summary>
     /// Доказывает, что pg_advisory_xact_lock в CreateVpnConfigCommandHandler реально защищает
     /// от гонки: при параллельных запросах ровно Quota проходят, остальные — 409 QuotaExceeded.
@@ -98,7 +100,7 @@ public class ConfigQuotaTests(PnvPanelWebApplicationFactory factory)
         Assert.Equal(ConcurrentAttempts - Quota, quotaExceeded);
 
         var myConfigsResponse = await userClient.GetAsync("/api/configs");
-        var myConfigs = await myConfigsResponse.ReadAsAsync<List<object>>();
-        Assert.Equal(Quota, myConfigs!.Count);
+        var myConfigs = await myConfigsResponse.ReadAsAsync<MyConfigsResponse>();
+        Assert.Equal(Quota, myConfigs!.Configs.Count);
     }
 }