Method CreateColumn

backend/Controllers/BoardsController.cs:202–224

(int id, [FromBody] CreateColumnDto dto)

    }

    [HttpPost("{id}/columns")]
    public async Task<IActionResult> CreateColumn(int id, [FromBody] CreateColumnDto dto)
    {
        var userId = int.Parse(User.FindFirstValue(ClaimTypes.NameIdentifier)!);
        try
        {
            var column = await _boardService.CreateColumnAsync(id, dto, userId);

            // Broadcast to other users
            await _hubContext.Clients.Group($"board_{id}")
                .SendAsync("ColumnCreated", column);

            return CreatedAtAction(nameof(GetBoardDetail), new { id = id }, column);
        }
        catch (KeyNotFoundException)
        {
            return NotFound();
        }
        catch (UnauthorizedAccessException)
        {
            return Forbid();
        }
    }

    [HttpPut("{id}/columns/{columnId}/move")]
    public async Task<IActionResult> MoveColumn(int id, int columnId, [FromBody] MoveColumnDto dto)