Credits & entitlements
Package and membership redemption
Find usable service credits for the booking date, consume exactly one credit, and restore it safely if the booking later qualifies for a return.
Accounting rule: credit consumption is written to its own ledger and uses idempotency so a retried booking command cannot deduct the same credit twice.
Package credit
Bound to a customer and eligible service with remaining quantity and expiry.
Membership credit
Bound to the active membership period and restored separately from cash refunds.