Each .lang carries a '# ver:' header (missing = v1) and langs.json carries
the catalog ver. An installed file whose ver differs from the catalog shows
a blue Update on its row (sub line shows 'code.lang vN'); updating the
ACTIVE language reboots on success to apply the fresh overlay, updating an
inactive one just refreshes the row. Downloads go to the immutable
/apps/lang/<ver>/<code>.lang path so the day-long edge cache can never
serve a stale file after a translation bump — same lesson as the flasher's
mutable-latest cache bite. The boot self-heal resolves the ver from the
catalog on the worker (flat-path fallback) and never reboots on its own.
Canonical files bumped to ver 2 (the full-coverage sweep).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
