Method CreateBoardInviteAsync

backend/Services/BoardService.cs:777–817

(int boardId, string role, int requesterId)

    }

    public async Task<BoardInviteDto> CreateBoardInviteAsync(int boardId, string role, int requesterId)
    {
        var board = await _db.Boards.Include(b => b.Members).FirstOrDefaultAsync(b => b.Id == boardId);

        if (board == null) throw new KeyNotFoundException("Board not found");

        // Only Workspace Owners or Admins can create board invites
        var workspace = await _db.Workspaces
            .Include(w => w.Members)
            .FirstOrDefaultAsync(w => w.Id == board.WorkspaceId);

        if (workspace == null) throw new KeyNotFoundException("Workspace not found");

        var isWsAdmin = workspace.OwnerId == requesterId ||
                        workspace.Members.Any(m => m.UserId == requesterId && m.Role == "Admin" && m.Status == "Accepted");

        if (!isWsAdmin)
            throw new UnauthorizedAccessException("Only workspace admins can create invite links for boards.");

        var invite = new BoardInvite
        {
            Token = Guid.NewGuid().ToString("N"),
            BoardId = boardId,
            Role = role,
            CreatorId = requesterId,
            CreatedAt = DateTime.UtcNow,
            IsActive = true
        };

        _db.BoardInvites.Add(invite);
        await _db.SaveChangesAsync();

        return new BoardInviteDto
        {
            Token = invite.Token,
            Role = invite.Role,
            BoardId = invite.BoardId,
            BoardName = board.Name,
            CreatedAt = invite.CreatedAt
        };
    }

    public async Task<BoardInviteDto?> GetBoardInviteByTokenAsync(string token)
    {