Add Hong Kong Traditional Chinese (zh-HK)

[Bin-Huang]

Summary

Add zh-HK (Traditional Chinese, Hong Kong wording) to the three surfaces that already support i18n: the admin console, the public docs and GET /v1/connectors.

• Locale tags: use region tags (zh-CN / zh-HK, later zh-TW), because the copy carries regional wording, not only a different script.
• Negotiation (src/i18n.ts): Intl.Locale.maximize() picks the script. zh-HK, zh-MO, zh-TW and zh-Hant resolve to zh-HK. zh, zh-SG and zh-Hans resolve to zh-CN. Accept-Language is ordered by q-value and q=0 is skipped.
• Copy source: zh-HK is derived from zh-CN with opencc-js (Simplified to Traditional glyphs, Taiwan glyph set) plus a short list of Hong Kong terms (帳戶, 登入, 建立, 儲存, 伺服器…). Docs and connector text convert at runtime, so they stay in sync with the zh-CN source.
• Console: public/admin-i18n.js gets a static zh-HK dictionary and zh-HK templates for dynamic messages. A test requires every console string to equal the server conversion, so a missing translation fails CI.
• Docs: language picker with 繁體中文（香港）, ?lang=zh-HK links and hreflang alternates.
• API/SDK: lang=zh-HK accepted; SDK type and docs updated.

Notes

• New runtime dependency: opencc-js (about 6 MB unpacked).
• The Hong Kong term list has not been reviewed by a native speaker yet.
• Not covered: end-user connect result pages (src/pages.ts, Chinese only today) and README.

Test plan

• npm run typecheck, npm run build
• npm test (59 passed)
• Checked the console (overview, settings language switch) and the docs site in zh-HK in a browser
• npm run test:browser (needs TEST_DATABASE_URL, not run)

🤖 Generated with Claude Code