Add user creation functionality: implement API endpoint for creating new users, including request handling and response management. Update frontend to support user creation with a new form in the UsersPanel, integrating role selection and input validation. Enhance i18n for new user-related strings.

backend/src/TeleWave.Api/Endpoints/AdminUserEndpoints.cs

@@ -1,6 +1,7 @@
 using LiteCqrs;
 using TeleWave.Api.Common;
 using TeleWave.Application.Admin.Users.BlockUser;
+using TeleWave.Application.Admin.Users.CreateUser;
 using TeleWave.Application.Admin.Users.DeleteUser;
 using TeleWave.Application.Admin.Users.GetUser;
 using TeleWave.Application.Admin.Users.ListUsers;
@@ -20,6 +21,7 @@ public static class AdminUserEndpoints
             .RequireAuthorization(policy => policy.RequireRole(RoleNames.Admin));
 
         admin.MapGet("", ListUsers).Produces<PagedList<UserSummaryDto>>();
+        admin.MapPost("", CreateUser).Produces<CreatedIdResponse>(StatusCodes.Status201Created);
         admin.MapGet("/{id:guid}", GetUser).Produces<UserSummaryDto>();
         admin
             .MapPost("/{id:guid}/block", BlockUser)
@@ -49,6 +51,21 @@ public static class AdminUserEndpoints
         return Results.Ok(result);
     }
 
+    private static async Task<IResult> CreateUser(
+        CreateUserBody body,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var result = await sender.Send(
+            new CreateUserCommand(body.UserName, body.Password, body.RoleId),
+            cancellationToken
+        );
+        return result.IsSuccess
+            ? Results.Created($"/api/admin/users/{result.Value}", new CreatedIdResponse(result.Value))
+            : result.ToHttpResult();
+    }
+
     private static async Task<IResult> GetUser(
         Guid id,
         ISender sender,
@@ -89,3 +106,5 @@ public static class AdminUserEndpoints
         return result.ToHttpResult();
     }
 }
+
+public sealed record CreateUserBody(string UserName, string Password, Guid RoleId);