теперь массив ошибок

backend/src/Tnsu.ApprovalRoute.Api/Common/ApiResponse.cs

@@ -2,4 +2,4 @@ namespace Tnsu.ApprovalRoute.Api.Common;
 
 public sealed record ApiResponse<T>(T Data);
 
-public sealed record ApiError(string Message);
+public sealed record ApiError(IReadOnlyList<string> Messages);

backend/src/Tnsu.ApprovalRoute.Api/Common/ResultExtensions.cs

@@ -24,9 +24,9 @@ public static class ResultExtensions
 
     private static IActionResult ToActionResult(this IError error) => error switch
     {
-        NotFoundError => new NotFoundObjectResult(new ApiError(error.Message)),
-        ValidationError => new BadRequestObjectResult(new ApiError(error.Message)),
-        ConflictError => new ConflictObjectResult(new ApiError(error.Message)),
-        _ => new ObjectResult(new ApiError(error.Message)) { StatusCode = StatusCodes.Status500InternalServerError }
+        NotFoundError => new NotFoundObjectResult(new ApiError([error.Message])),
+        ValidationError => new BadRequestObjectResult(new ApiError([error.Message])),
+        ConflictError => new ConflictObjectResult(new ApiError([error.Message])),
+        _ => new ObjectResult(new ApiError([error.Message])) { StatusCode = StatusCodes.Status500InternalServerError }
     };
 }

backend/src/Tnsu.ApprovalRoute.Api/Filters/ValidationActionFilter.cs

@@ -25,7 +25,7 @@ public sealed class ValidationActionFilter(IServiceProvider serviceProvider) : I
                 continue;
 
             context.Result = new BadRequestObjectResult(
-                new ApiError(string.Join(" ", result.Errors.Select(e => e.ErrorMessage))));
+                new ApiError(result.Errors.Select(e => e.ErrorMessage).ToList()));
             return;
         }