CLI-side glue that assembles harn-vm’s layered skill discovery
from the inputs harn run / harn test / harn check see at
startup: repeatable --skill-dir, $HARN_SKILLS_PATH, the nearest
harn.toml, and the user’s home / system directories.
Schema version stamped on every provider dispatch-audit envelope (the
report and its embedded tool-probe plan). Re-exported from the crate root as
the single source of truth so integration tests reference it instead of
duplicating the number — the duplication that let this rot silently while the
slow-E2E tier was unwatched. The in-crate audit unit tests still pin the
literal value, so an intentional bump remains a deliberate, reviewed change.