Method UpdateComment

backend/Controllers/TasksController.cs:249–269

(int activityId, [FromBody] AddCommentDto dto)

    }

    [HttpPut("activities/{activityId}")]
    public async Task<IActionResult> UpdateComment(int activityId, [FromBody] AddCommentDto dto)
    {
        try
        {
            int userId = GetUserId();
            var activity = await _taskService.UpdateActivityAsync(activityId, dto.Text, userId);
            if (activity == null) return Forbid();

            // Notify board
            var task = await _taskService.GetTaskByIdAsync(activity.TaskCardId, userId);
            if (task != null)
            {
                await _hubContext.Clients.Group($"board_{task.BoardId}")
                    .SendAsync("TaskUpdated", task);
            }

            return Ok(activity);
        }
        catch (UnauthorizedAccessException) { return Forbid(); }
    }

    [HttpPost("activities/{activityId}/reactions")]
    public async Task<IActionResult> ToggleReaction(int activityId, [FromBody] ToggleReactionDto dto)