reserveEquipment was check-then-insert with no DB guard: two concurrent
requests both passed the in-memory overlap check and double-booked a
machine. Migration 042 adds btree_gist + a GiST EXCLUDE constraint
(equipment_id =, tstzrange && ) WHERE status='reserved', making the DB
the arbiter; the action maps the 23P01 violation to the existing
friendly overlap message. App-side check kept as a fast pre-check.
Schema + DB maps updated.
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.
Moheeb Zara