Data model

Lists

Models registered in features/keystone/models/index.ts:

Area	Models
Tenant and people	`Organization`, `User`, `Role`, `Member`, `MemberImportRecord`, `ContactMessage`
Settings and sites	`GymSettings`, `Location`, `GymResource`
Memberships	`MembershipTier`, `Membership`, `MembershipCreditGrant`, `MembershipCreditEntry`, `Subscription`
Classes	`ClassType`, `ClassSchedule`, `ClassInstance`, `ClassBooking`, `Waitlist`, `AttendanceRecord`, `Instructor`
Check-in	`CheckIn`
Personal training	`TrainerAvailability`, `TrainerAppointment`, `TrainingPackage`, `TrainingCreditEntry`, `CoachingAssignment`, `TrainingLead`
Workouts	`Exercise`, `WorkoutLog`, `WorkoutSet`
Payments	`MembershipPayment`, `GymPayment`, `PaymentMethod`, `PaymentProvider`, `PaymentSession`, `PaymentEvent`, `MembershipBillingAttempt`, `GymRefundAttempt`, `CounterPaymentAttempt`
Retail	`RetailItem`, `RetailSale`, `RetailReturn`, `RetailStockEntry`, `RetailClose`
Operations	`OperationalNotice`, `ParticipationPolicy`, `ParticipationEvidence`, `OperationsCase`, `IntegrationCredential`
System	`OnboardingRun`, `StaffIntent`, `AuthRateLimitBucket`

Some notes on how they fit:

Class booking works on dated ClassInstance rows. Each booking is confirmed, waitlist, or cancelled. The separate Waitlist model is an older schedule-level list; live booking uses the per-session waitlist on ClassBooking.
Class credits come from a MembershipCreditGrant per service period, with every change in MembershipCreditEntry.
Training packages hold prepaid credits. Each use, refund, or adjustment is a TrainingCreditEntry.
StaffIntent stores the exact form request a person submitted, so a lost response can be retried without applying it twice.
CounterPaymentAttempt records a counter card sale or refund before Stripe is called.