Resolve language-file conflicts by taking master's English-removal
cleanup across non-English locales, while stripping the MailChimp
keys master reintroduced (already moved to MailchimpPlugin on this
branch) and reapplying this branch's plugins/integrations rename and
new Module.php plugins keys where master lacked them.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
- Replace untranslated English strings with empty fallback ('') across all non-English catalogs and sort keys alphabetically (closes#4783, closes#4660)
- Restore missing Sales.no_sales_to_display in English while preserving existing translations (closes#4794, references #4637, #4795)
- Register Georgian (ka) and Swahili (sw-KE, sw-TZ) locales, normalize Croatian to hr per BCP 47, and fix datepicker long month keys (partially addresses #4476, references #3891)
- Hardcode invariant brand constants (OSPOS, website, copyrights) in login/footer views, remove from catalogs, and standardize Latin OSPOS branding
- Fix English catalog typos and maintain consistent British English variants in en-GB
- Add LanguageFilesTest with 4,418 automated tests for syntax, key parity, sorting, and bidirectional locale registrations
- Update AGENTS.md with localization guidelines and development best practices
