Method MoveTaskAsync

backend/Services/TaskService.cs:156–206

(int taskId, MoveTaskDto dto, int userId)

    }

    public async Task<TaskCardDto?> MoveTaskAsync(int taskId, MoveTaskDto dto, int userId)
    {
        Console.WriteLine($"[MoveTask] Moving Task {taskId} to Column {dto.TargetColumnId} at Order {dto.NewOrder}");
        var task = await _db.TaskCards
            .Include(t => t.Column)
            .Include(t => t.Assignee)
            .Include(t => t.Assignees).ThenInclude(a => a.User)
            .Include(t => t.Subtasks)
            .Include(t => t.Attachments).ThenInclude(a => a.UploadedBy)
            .Include(t => t.TimeLogs)
            .FirstOrDefaultAsync(t => t.Id == taskId);

        if (task == null) return null;

        if (!await VerifyTaskAccessAsync(taskId, userId))
            throw new UnauthorizedAccessException("User does not have access to this task.");

        int oldColumnId = task.ColumnId;

        // 1. Get all tasks in the target column (excluding the moved task)
        var targetColumnTasks = await _db.TaskCards
            .Where(t => t.ColumnId == dto.TargetColumnId && t.Id != taskId)
            .OrderBy(t => t.Order)
            .ToListAsync();

        // 2. Insert the moved task at the new position
        int newIndex = Math.Max(0, Math.Min(dto.NewOrder, targetColumnTasks.Count));

        task.ColumnId = dto.TargetColumnId;

        targetColumnTasks.Insert(newIndex, task);

        // 3. Update Order for all tasks in the target column
        for (int i = 0; i < targetColumnTasks.Count; i++)
        {
            targetColumnTasks[i].Order = i;
        }

        await _db.SaveChangesAsync();

        if (oldColumnId != dto.TargetColumnId)
        {
            await LogActivity(taskId, userId, "Moved", $"Moved to column {dto.TargetColumnId}");
        }
        else
        {
            await LogActivity(taskId, userId, "Reordered", "Reordered within same column");
        }

        return await MapToDto(task);
    }

    public async Task<int?> DeleteTaskAsync(int taskId, int userId)
    {