fix(StockCompareModal): 修复对比差异单位显示错误

- 将差异列单位统一改为 % 格式
- 移除 pp（百分点）单位的特殊处理

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/views/Company/components/StockQuoteCard/components/StockCompareModal.tsx

@@ -152,9 +152,7 @@ const StockCompareModal: React.FC<StockCompareModalProps> = ({
                                   {diff > 0 && <ArrowUp size={12} />}
                                   {diff < 0 && <ArrowDown size={12} />}
                                   <Text>
-                                    {metric.format === 'percent'
-                                      ? `${Math.abs(diff).toFixed(2)}pp`
-                                      : `${Math.abs(diff).toFixed(2)}%`}
+                                    {`${Math.abs(diff).toFixed(2)}%`}
                                   </Text>
                                 </HStack>
                               ) : (