Both importers already read a package's embedded faces and register them, but
nothing wrote them back: a document set in a font nobody has installed lost its
look on the next machine. ODF gets plain TTFs under Fonts/ with a manifest entry
each, merged into the font-face declaration the name already has; Word gets a
per-part GUID, an obfuscated .odttf and its w:embed... in the family's w:font.
The picker lists the families too, and a slow store read no longer replaces the
faces of a file opened while it was still running.