docs(zh-CN): complete Chinese README with CN-native market framing

[xinqi5921]

Path A submission for bounty #12445

What changed

• Complete zh-CN README translation (362 lines, 13,454 characters)
• CN-native cultural framing: 华强北 × 闲鱼 × 企业淘汰硬件回收
• Anti-VM-farm fairness notes for Chinese miners
• E-waste crisis context resonating with Chinese audience

Bounty claim

/claim #12445

GitHub: xinqi5921

[github-actions]

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