[FEATURE]: Sync zh-cn agents doc page with the latest English version

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Describe the enhancement you want to request

The Chinese translation of the agents page (packages/web/src/content/docs/zh-cn/agents.mdx) is out of sync with the English version:

• Missing the Tools (deprecated) marker and the deprecation notice (the English page states tools is deprecated in favor of permission, and that true/false is equivalent to allow/deny)
• The Permissions section still lists only edit, bash and webfetch while the English page documents the full permission key list
• Other content added since the last sync (e.g. the scout agent section) is missing

The page was last updated 2026-05-08; the English version is 781 lines vs 754 for zh-cn.

Additionally, the translation should use the unified terminology 智能体 (consistent with PR #41980 and the zh.ts UI strings).

This will be fixed by re-translating the whole page against the latest English version in a follow-up PR.