Absolute filesystem path to the skill directory
OptionalqualifierPrefixes the names of skills beneath this root, as <qualifier>:<name>. Skills are addressed
by one global name, so two artifacts shipping the same skill name could not otherwise coexist -
and renaming the directory instead would change the artifact's content hash. Must be a single
path segment, so that it can be told from the skill name it is joined to.
Tier the directory belongs to
A skill directory paired with the tier it originates from.