更新首页二维码，优化部分页面显示，更新 readme

src/app/admin/channels/page.tsx

@@ -197,18 +197,6 @@ export default function ChannelsPage(props: ChannelsPageProps) {
           onSizeChange: size => refresh(1, size),
         }}
         columns={[
-          {
-            header: '批次号',
-            cell: ({row}) => {
-              const channel = row.original
-              const expired = isExpired(channel.expired_at)
-              return (
-                <div className={`${expired ? 'text-weak' : ''}`}>
-                  <span>{row.original.batch_no}</span>
-                </div>
-              )
-            },
-          },
           {
             header: '代理地址',
             cell: ({row}) => {