i18n(ru): add Russian locale for documentation site

[Nikitamce]

Summary

Adds a full Russian (ru) locale to the ScriptCat documentation site (Docusaurus).

Changes

• docusaurus.config.js: register ru / «Русский» next to zh-Hans and en
• i18n/ru/code.json: homepage and product UI strings
• i18n/ru/docusaurus-theme-classic/*: navbar & footer labels
• i18n/ru/docusaurus-plugin-content-docs/: all current docs
  • User guide (install, open-dev, sync, VS Code, migrate from TM/VM, FAQ)
  • Policies (disclaimer, privacy)
  • Developer docs (API, background, meta, CloudCat, Agent suite)
  • Changelogs (v0.16–v1.5, main index, beta changelog)

Notes

• Product names, API identifiers, code blocks, and URLs are kept as-is
• Images are carried over from the English locale tree where needed

Test plan

• pnpm i && pnpm start -- --locale ru
• Language dropdown shows Русский
• /ru/ homepage and navbar are in Russian
• Spot-check /ru/docs/use/use/, /ru/docs/dev/, /ru/docs/change/
• Build succeeds: pnpm build

[CodFrm]

Thank you very much, I will review it in a couple of days.

[CodFrm]

Thanks for the Russian localization contribution! I’ve pushed a follow-up commit to address the issues found during review.

The main maintenance change is that Russian changelog pages now use the English changelog as their single source of truth. Updating i18n/en/.../change/*.md and rebuilding the site will automatically update the corresponding /ru/docs/change/... pages. The Russian URLs remain unchanged, and the pages will not fall back to Chinese.

The follow-up also:

• fixes the broken Russian anchors and locale-aware links;
• corrects the privacy-policy data-retention wording and the @connect permission semantics;
• extends the i18n/frontmatter checks to cover all locales;
• adds a production-output check to ensure the 9 Russian changelog pages continue to use the English source;
• updates the URL inventory with the 49 new /ru/ routes;
• localizes the Russian SEO metadata.

Validation completed successfully:

• pnpm run typecheck
• full production build for zh-Hans, en, and ru
• pnpm run check (147 routes, 9 configured fallbacks, i18n parity, and frontmatter)
• generated HTML checks for changelog content, links, anchors, privacy wording, and API permission wording

The PR is now clean and mergeable from my side.

[Nikitamce]

thank you very much, If there’s anything else that needs to be added or fixed on my side, just let me know — I’ll correct or complete it so there are no issues.