Add three Chinese locale variants with region-specific flags: - zh-TW: Traditional Chinese (Taiwan) 🇹🇼 - zh-HK: Traditional Chinese (Hong Kong) 🇭🇰 - zh-CN: Simplified Chinese (China) 🇨🇳 Each variant uses region-appropriate terminology (e.g. 郵件/電郵/邮件 for "email"), consistent with the existing pattern of tying languages to specific regions (e.g. Spanish (Spain), Portuguese with 🇧🇷). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>