* fix(media-use): tests never write into the person's media library
* fix(media-use): guard the media home only in this repo's test runs
* test(media-use): probe the media home from a plain child process
* fix(media-use): keep miss logging best-effort when home is unresolvable
* test(media-use): miss logging survives an unresolvable media home
* docs(media-use): describe the media library without naming an app
* chore(media-use): refresh the skills manifest hash