DropdownMenu 展开后宽度只能整屏宽吗，可否支持宽度自定义

TDDropdownMenu`(
        direction: TDDropdownMenuDirection.down,
        width: MediaQuery.of(context).size.width - 24.w,
        items: [
          TDDropdownItem(
            label: '距离',
            options: [
              TDDropdownItemOption(
                label: '500米',
                value: '500',
                selected: selectedDistance == '500',
              ),
              TDDropdownItemOption(
                label: '1 公里',
                value: '1000',
                selected: selectedDistance == '1000',
              ),
              TDDropdownItemOption(
                label: '2 公里',
                value: '2000',
                selected: selectedDistance == '2000',
              ),
              TDDropdownItemOption(
                label: '5 公里',
                value: '5000',
                selected: selectedDistance == '5000',
              ),
              TDDropdownItemOption(
                label: '10 公里',
                value: '10000',
                selected: selectedDistance == '10000',
              ),
            ],
            onChange: (value) {
              print('距离下拉选择器选中值: $value');
              final val = value[0];
              selectedDistance = val as String?;
            },
          )
        ],
        onMenuOpened: (value) {
          print('打开机构类型菜单');
        },
        onMenuClosed: (value) {
          print('关闭机构类型菜单');
        },
      )

给TDDropdownMenu设置宽度后，展开的菜单仍然为全屏宽度，是否可以支持设置展开后菜单宽度，或者展开后菜单跟随TDDropdownMenu宽度，保证两者样式统一

Start at the TDDropdownMenu API and reproduce the example showing that the expanded menu remains full width despite the configured width. Trace how the menu width is determined; done means the expanded menu follows TDDropdownMenu's width or provides a separate explicit width option, with matching styling.