Every resource root's index for a package's locales, highest precedence first.
The index subsumes the older manifest.json pair (package index + per-locale manifest) into one
file; callers fall back to those when a root predates it or a user hand-dropped a folder.
Every resource root's index for a package's locales, highest precedence first.
The index subsumes the older
manifest.jsonpair (package index + per-locale manifest) into one file; callers fall back to those when a root predates it or a user hand-dropped a folder.