Vendors carrier's locales/en-US/main.ftl (extended to cover gsmol's
remaining strings) as the single source both clients draw wording
from, adds a dependency-free .ftl-to-JSON build step (devbox run
locale) since the file only ever uses Fluent's flat subset, and
replaces every hardcoded string in index.html/app.js with a lookup
into the generated dictionary.
Along the way: removes connect()'s requirePin check, which turned out
to be unreachable under the app's own invariants (every call site
already guarantees its target host is pinned before calling it), and
fixes a leftover call to store.setMasterSaved — removed in the earlier
settings redesign — that was silently breaking onboarding's "I saved
it" button.
