Update simplified chinese translation

[gongfuture]

Checklist

• Tested the change ingame
• Provided screenshots if it is a visual change
• Tested in combination with possibly related configuration options
• Written a unit test (especially base/) or added coverage to integration test
• Considered possible null pointers and out of bounds array indexing
• Changed no physics that affect existing maps
• Tested the change with ASan+UBSan or valgrind's memcheck (optional)
• I didn't use generative AI to generate more than single-line completions

• Improve some of the existing translations
• Translate the added parts

[Copilot]

Pull request overview

This PR updates the simplified Chinese translation file to improve existing translations and complete previously untranslated strings. The updates make the Chinese text more natural, clearer, and more accurate for Chinese-speaking users.

• Improves translation quality and clarity across multiple UI elements and settings
• Standardizes terminology (e.g., "尾迹" → "拖尾" for "trail", "表情符号" → "颜文字" for "Kaomoji")
• Completes 9 previously untranslated strings with proper Chinese translations
• Adds visual kaomoji examples alongside their Chinese descriptions for better user understanding

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[SollyBunny]

Lgtm