♻️ Refactor: Move token unit toggle from table header to filter settings

- Remove K/M switch from model price column header in pricing table
- Add "Display in K units" option to pricing display settings panel
- Update parameter passing for tokenUnit and setTokenUnit across components:
  - PricingDisplaySettings: Add tokenUnit toggle functionality
  - PricingSidebar: Pass tokenUnit props to display settings
  - PricingFilterModal: Include tokenUnit in mobile filter modal
- Enhance resetPricingFilters utility to reset token unit to default 'M'
- Clean up PricingTableColumns by removing unused setTokenUnit parameter
- Add English translation for "按K显示单位" as "Display in K units"

This change improves UX by consolidating all display-related controls
in the filter settings panel, making the interface more organized and
the token unit setting more discoverable alongside other display options.

Affected components:
- PricingTableColumns.js
- PricingDisplaySettings.jsx
- PricingSidebar.jsx
- PricingFilterModal.jsx
- PricingTable.jsx
- utils.js (resetPricingFilters)
- en.json (translations)

web/src/i18n/locales/en.json

@@ -950,7 +950,7 @@
   "黑夜模式": "Dark mode",
   "管理员设置": "Admin",
   "待更新": "To be updated",
-  "定价": "Pricing",
+  "模型广场": "Pricing",
   "支付中..": "Paying",
   "查看图片": "View pictures",
   "并发限制": "Concurrency limit",
@@ -1195,6 +1195,7 @@
   "兑换码创建成功，是否下载兑换码？": "Redemption code created successfully. Do you want to download it?",
   "兑换码将以文本文件的形式下载，文件名为兑换码的名称。": "The redemption code will be downloaded as a text file, with the filename being the redemption code name.",
   "模型价格": "Model price",
+  "按K显示单位": "Display in K units",
   "可用分组": "Available groups",
   "您的默认分组为：{{group}}，分组倍率为：{{ratio}}": "Your default group is: {{group}}, group ratio: {{ratio}}",
   "按量计费费用 = 分组倍率 × 模型倍率 × （提示token数 + 补全token数 × 补全倍率）/ 500000 （单位：美元）": "The cost of pay-as-you-go = Group ratio × Model ratio × (Prompt token number + Completion token number × Completion ratio) / 500000 (Unit: USD)",