🎨 refactor(ui): use lucide-react for search/refresh and chevron icons

- DashboardHeader.jsx: replace Semi's IconSearch/IconRefresh with lucide-react's Search/RefreshCw (size 16), preserve existing button styles
- UptimePanel.jsx: replace Semi's IconRefresh with lucide-react's RefreshCw (size 14), keep styling intact
- UserArea.jsx: replace Semi's IconChevronDown with lucide-react's ChevronDown (size 14), preserve visual parity
- Update imports: remove @douyinfe/semi-icons usage where replaced; add lucide-react imports
- Verified no remaining IconSearch/IconRefresh in dashboard; no new linter errors

Motivation: unify icon library for core actions and improve UI consistency.
Follow-ups: consider migrating remaining Semi icons (e.g., plus/minus, charts) to lucide-react.

web/src/i18n/locales/en.json

@@ -1788,7 +1788,7 @@
   "将仅保留第一个密钥文件，其余文件将被移除，是否继续？": "Only the first key file will be retained, and the remaining files will be removed. Continue?",
   "自定义模型名称": "Custom model name",
   "启用全部密钥": "Enable all keys",
-  "以充值价格显示": "Recharge price",
+  "充值价格显示": "Recharge price",
   "美元汇率（非充值汇率，仅用于定价页面换算）": "USD exchange rate (not recharge rate, only used for pricing page conversion)",
   "美元汇率": "USD exchange rate",
   "隐藏操作项": "Hide actions",