Add scripts/check_translations.py and a lightweight Translations workflow
that runs it (no Android SDK needed) so Weblate PRs get fast feedback. The
script fails on stale keys (present in a translation but not the base) and on
translating translatable="false" entries; missing keys are reported as
coverage only.
Downgrade lint's MissingTranslation to informational: partial community
translations are expected and fall back to the English base at runtime.
Stale/extra keys (ExtraTranslation) remain fatal in lintDebug.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
