feat: 个股日K信息条支持自定义指标(扩展数据/财务/单独显示)

- 信息条(StockInfoBar)行末加配置齿轮,复用自选列表抽屉自定义显示项
- 新增指标: 成交量/振幅/开高低 + 扩展数据(ext) + 财务(EPS/BPS/ROE/PE/PB等)
- 后端 klineDaily 新增 ext_columns 参数,按 symbol JOIN 扩展数据
- 财务数据前端直拉 useFinancialMetrics, PE/PB 用现价现算
- 每列可设单独显示(standalone),独占一行渲染
- ext 标签支持 maxTags 截断 + 点击 +N 同页展开/收起
- 修复重开弹窗信息条消失(symbol 重置与子组件 onDataChange 竞态)
- 修复 ext 勾选不显示(query key 未含 extColumns 导致缓存命中)
- 配置按钮左侧加监控通知图标占位(BellRing)
- ListColumnCustomizer 新增 showExtColumns/showStandaloneToggle prop

frontend/src/lib/queryKeys.ts

@@ -48,8 +48,8 @@ export const QK = {
   analysisMenu:         (id: string) => ['analysis-menu', id] as const,
 
   // Kline
-  kline:                (symbol: string, start: string, end: string) =>
-                           ['kline', symbol, start, end] as const,
+  kline:                (symbol: string, start: string, end: string, extColumns?: string) =>
+                           ['kline', symbol, start, end, extColumns ?? ''] as const,
   klineMinute:          (symbol: string, date: string) =>
                              ['kline-minute', symbol, date] as const,
   indexDaily:           (symbol: string, start: string, end: string) =>