Method AddLabelToTaskAsync

backend/Services/TaskService.cs:854–869

Label Methods Implementation

(int taskId, int labelId, int userId)

    // Label Methods Implementation
    public async Task<bool> AddLabelToTaskAsync(int taskId, int labelId, int userId)
    {
        if (!await VerifyTaskAccessAsync(taskId, userId))
            throw new UnauthorizedAccessException("User does not have access to this task.");

        var existing = await _db.TaskLabels.AnyAsync(tl => tl.TaskCardId == taskId && tl.LabelId == labelId);
        if (existing) return true;

        _db.TaskLabels.Add(new TaskLabel { TaskCardId = taskId, LabelId = labelId });
        await _db.SaveChangesAsync();

        var label = await _db.Labels.FindAsync(labelId);
        await LogActivity(taskId, userId, "Label Added", $"Added label: {label?.Name ?? "Unknown"}");

        return true;
    }

    public async Task<bool> RemoveLabelFromTaskAsync(int taskId, int labelId, int userId)
    {