equipment.ts: registry CRUD (equipment.manage; delete refused once
reservations exist, archive instead), listEquipmentForMembers (active
items with a member_certified flag computed via the service client),
reserveEquipment / cancelReservation as validated service-client writes
that enforce status, no-overlap and the required-certification gate with
an equipment.manage override (and manager booking on a member's behalf),
listEquipmentReservations and getMyReservations. equipment-guard mirrors
the other module guards. Barrel + API_REFERENCE updated.
