feat(i18n): add storage details cooldown and timeout setting labels

[Vurliy]

Summary / 摘要

1. Context & Motivation / 背景与动机

This PR accompanies the backend PR OpenListTeam/OpenList (which introduces asynchronous context decoupling, force-refresh cache invalidation, and singleflight deduplication for storage quota probing).

It adds the corresponding English i18n labels in src/lang/en/settings.json for the two newly introduced configuration options in the Admin Settings panel:
本 PR 配合后端 OpenListTeam/OpenList 的存储容量探测优化，在 src/lang/en/settings.json 中为管理后台新增的两个配置项提供标准英文国际化词条：

• storage_details_cooldown_seconds: "Storage details refresh cooldown (seconds)"
  Cooldown duration in seconds to throttle high-frequency capacity queries (defaults to 0).
  存储容量刷新冷却时间（秒，默认 0 秒）。
• storage_details_timeout_seconds: "Storage details background timeout (seconds)"
  Independent timeout duration in seconds for background storage details probing (defaults to 15s).
  存储容量后台探测超时时间（秒，默认 15 秒）。

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2. Changes / 变更内容

• Added storage_details_cooldown_seconds and storage_details_timeout_seconds to src/lang/en/settings.json.

• This PR has breaking changes. / 此 PR 包含破坏性变更。

• This PR changes public API, config, storage format, or migration behavior. / 此 PR 修改了公开 API、配置、存储格式或迁移行为。

• This PR requires corresponding changes in related repositories. / 此 PR 需要关联仓库同步修改。

Related repository PRs / 关联仓库 PR:

• OpenList: fix(storage): decouple details context, invalidate cache on refresh, and add singleflight OpenList#2950

Related Issues / 关联 Issue

• Relates to OpenList无法显示各个网盘的容量大小了 OpenList#1815, [BUG] 别名容量显示错误 OpenList#2633, [BUG] 别名容量显示错误 OpenList#2635

Testing / 测试

• Verified admin settings page renders translated labels properly when backend settings API returns the new keys.

Checklist / 检查清单

• I have read CONTRIBUTING. / 我已阅读 CONTRIBUTING。
• I confirm this contribution follows the repository license, contribution policy, and code of conduct. / 我确认此贡献符合仓库许可证、贡献规范和行为准则。
• I have formatted the changed code with prettier where applicable. / 我已按适用情况使用 prettier 格式化变更代码。
• I have requested review from relevant maintainers or code owners where applicable. / 我已在适用情况下请求相关维护者或代码所有者审查。

AI Disclosure / AI 使用声明

• This PR includes AI-assisted content. / 此 PR 包含 AI 辅助内容。

Tools used / 使用工具:

• Gemini

Usage scope / 使用范围:

• Documentation / 文档

• Translation / 翻译

• Review assistance / 审查辅助

• I have reviewed and validated all AI-assisted content included in this PR. / 我已审核并验证此 PR 中的所有 AI 辅助内容。

• I have ensured that all AI-assisted commits include Co-Authored-By attribution. / 我已确保所有 AI 辅助提交都包含 Co-Authored-By 归属信息。

• I can reproduce all AI-assisted content included in this PR without any AI tools. / 我可以在没有任何 AI 工具的情况下重现此 PR 中包含的所有 AI 辅助内容。