Component values by key, hashes computed lazily via snapshotOf.
Final tombstone state for the path — explicit ifclite::deleted
opinions plus subtree shadowing (a tombstoned parent deletes its
descendants, exactly as composition does).
True only when the strongest ifclite::deleted opinion on THIS path
is a tombstone. Shadow deaths (a deleted ancestor) leave it false —
the matrix must not emit its own delete op for those: the parent's
tombstone already shadows the subtree at composition time, and the
parent may itself be in conflict.
Inheritance slots: role name → inherited path.
Child slots: role name → child path.