fix(i18n): add and polish zh-rCN translations

[Jursin]

Objective

Add and polish the Simplified Chinese (values-zh-rCN) translations.

Implementation

Resource-only change to values-zh-rCN/strings.xml.

Testing

• strings.xml is well-formed and key-parity with values/strings.xml verified.
• Resource-only change; no code touched.

Checklist

• Code follows the existing Kotlin/Compose style.
• Code compiles locally without new warnings.
• No unnecessary third-party dependencies were introduced.
• Commits are logical and well-described.

Screenshots (if applicable)

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[github-actions]

🤖 AI Triage

This PR consists entirely of well-formed Simplified Chinese (zh-rCN) string translation polish and additions in manager/src/main/res/values-zh-rCN/strings.xml.

Note: this is an automated AI bot (Gemini); its verdict isn't 100% accurate and can be wrong. The bot doesn't read or reply to further comments in this thread — if it got this wrong, ping a human maintainer.