refactor: 移除仓位资产列

- 列表只显示总余额和跟单数
- 移除仓位资产列
- 移动端卡片移除仓位资产Tag

frontend/src/pages/LeaderList.tsx

@@ -247,28 +247,6 @@ const LeaderList: React.FC = () => {
         return <Text ellipsis={{ tooltip: remark }} style={{ maxWidth: 180 }}>{remark}</Text>
       }
     },
-    {
-      title: t('leaderDetail.positionBalance'),
-      key: 'positionAsset',
-      width: 150,
-      render: (_: any, record: Leader) => {
-        const balance = balanceMap[record.id]
-        if (!balance) return <Spin size="small" />
-        const displayText = balance.position === '-' ? '-' : `${formatUSDC(balance.position)} USDC`
-        return <Text style={{ color: '#722ed1', fontSize: '14px' }}>{displayText}</Text>
-      }
-    },
-    {
-      title: t('leaderDetail.positionBalance'),
-      key: 'positionAsset',
-      width: 150,
-      render: (_: any, record: Leader) => {
-        const balance = balanceMap[record.id]
-        if (!balance) return <Spin size="small" />
-        const displayText = balance.position === '-' ? '-' : `${formatUSDC(balance.position)} USDC`
-        return <Text style={{ color: '#722ed1', fontSize: '14px' }}>{displayText}</Text>
-      }
-    },
     {
       title: t('leaderDetail.totalBalance'),
       key: 'balance',
@@ -371,9 +349,6 @@ const LeaderList: React.FC = () => {
 
                       <div style={{ display: 'flex', gap: '8px', marginBottom: '12px', flexWrap: 'wrap' }}>
                         <Tag color="cyan">{leader.copyTradingCount} {t('leaderList.copyTradingCount')}</Tag>
-                        {balance && balance.position !== '-' && balance.position !== '0' && (
-                          <Tag color="purple">{t('leaderDetail.positionBalance')}: {formatUSDC(balance.position)}</Tag>
-                        )}
                       </div>
 
                       {leader.remark && (