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.Application.Tests/Admin/Users/ChangeUserRoleCommandHandlerTests.cs

@@ -2,6 +2,7 @@ using NSubstitute;
 using PnvPanel.Application.Admin.Users;
 using PnvPanel.Application.Common.Interfaces;
 using PnvPanel.Application.Common.Models;
+using PnvPanel.Application.Tests.TestSupport;
 using Xunit;
 
 namespace PnvPanel.Application.Tests.Admin.Users;
@@ -9,35 +10,42 @@ namespace PnvPanel.Application.Tests.Admin.Users;
 public class ChangeUserRoleCommandHandlerTests
 {
     private readonly IRoleService _roleService = Substitute.For<IRoleService>();
+    private readonly ICurrentUser _currentUser = Substitute.For<ICurrentUser>();
 
     [Fact]
     public async Task Handle_DelegatesToRoleServiceAndReturnsSuccess()
     {
+        using var dbContext = InMemoryDbContextFactory.Create();
+
         var userId = Guid.NewGuid();
         var roleId = Guid.NewGuid();
         _roleService.ChangeUserRoleAsync(userId, roleId, Arg.Any<CancellationToken>()).Returns(Result.Success());
 
-        var handler = new ChangeUserRoleCommandHandler(_roleService);
+        var handler = new ChangeUserRoleCommandHandler(_roleService, dbContext, _currentUser);
 
         var result = await handler.Handle(new ChangeUserRoleCommand(userId, roleId), CancellationToken.None);
 
         Assert.True(result.IsSuccess);
         await _roleService.Received(1).ChangeUserRoleAsync(userId, roleId, Arg.Any<CancellationToken>());
+        Assert.Single(dbContext.AuditLogs.Local);
     }
 
     [Fact]
     public async Task Handle_WhenRoleServiceFails_PropagatesFailure()
     {
+        using var dbContext = InMemoryDbContextFactory.Create();
+
         var userId = Guid.NewGuid();
         var roleId = Guid.NewGuid();
         var error = UserErrors.NotFound;
         _roleService.ChangeUserRoleAsync(userId, roleId, Arg.Any<CancellationToken>()).Returns(Result.Failure(error));
 
-        var handler = new ChangeUserRoleCommandHandler(_roleService);
+        var handler = new ChangeUserRoleCommandHandler(_roleService, dbContext, _currentUser);
 
         var result = await handler.Handle(new ChangeUserRoleCommand(userId, roleId), CancellationToken.None);
 
         Assert.False(result.IsSuccess);
         Assert.Equal(error, result.Error);
+        Assert.Empty(dbContext.AuditLogs.Local);
     }
 }