Audit of the same failure family as the shrunk drawables: references by
NAME that nothing validates at compile time.
The whole onboarding and release-notes feature had never shipped. Reading
the installed APK: ZERO entries under assets/content/, while
assets/icons/alarmas/* was present. pubspec declared `assets/content/`, and
Flutter does not recurse -- naming a directory includes the files sitting
directly in it, never its subdirectories. Every content file lives in one
(onboarding/, updates/<locale>/), so none of them were packaged.
On the device that surfaced on every single launch:
Unable to load asset: "assets/content/onboarding/en.md"
with the file plainly present on disk. That is why it never looked like a
packaging problem. The tell was already in the pubspec: assets/icons/alarmas/
is listed explicitly, so the rule was known once and not applied here.
All 14 content directories are now declared: onboarding/ plus updates/ for
each of the 13 locales.
The guard is a test that loads every file under assets/content/ through
rootBundle, because that is the only thing that proves an asset is declared
and will ship. A test asserting File.existsSync would have stayed green
through all of this -- the files were never missing, only unpackaged. Run
against the unfixed pubspec it fails 26 of 27; with the fix it passes.
Tests: 1165 -> 1192.
