fix(i18n): add missing translation keys for signatures and email import
Fixes 25 failing tests across translations and eml-import test suites:
- Add 141 missing i18n keys to en/common.json for P2.1 (extended signatures
feature) and P2.5 (email import feature). Keys cover:
- signatures.* (signature editor, toolbar labels, per-identity settings)
- settings.importer.* (mail import UI labels and messages)
- settings.tabs.signatures, settings.{loading,refresh}
- email_composer.{insert_signature,no_signature,select_signature}
- identities.form.{signature_store_*,use_global_default}
- calendar.{edit,delete,duplicate}, contacts.{edit,delete,send_email}
- contacts.import.csv_* (CSV column mapping labels)
- Other related keys for sharing, mailbox context menu, file operations
- Propagate new keys to all 23 other locale files:
- ar, ca, cs, da, de, es, fa, fr, he, hu, it, ja, ko, lv, nl, pl, pt, ro,
ru, sk, tr, uk, zh
- 19 locales with real, idiomatic translations matching existing tone
- 4 locales (da, es, fa, zh) with English placeholders pending native
translation
- Fix eml-import test: update accept-string expectation to match actual
EML_IMPORT_ACCEPT constant (now includes .tgz, .tar.gz, application/gzip
support added in P2.5)
All 53 tests now pass:
- 48 translation completeness tests
- 5 eml-import tests
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
