Service code layout

Put business logic in app/services by default (one package, domain-oriented files). Extract into app/* domain packages only for small, pure, testable helpers that do not need HTTP/Facades orchestration.

Conventions

1. CRUD / code-generator modules live in app/services to match templates.
2. Cross-domain orchestration (payment apply, tenant connection, export/import enqueue) stays in app/services — do not add a ports layer just for orchestration.
3. Existing domain packages: app/payment, app/search, app/rbac, app/tenancy. Do not create app/<domain> by default (e.g. no app/notice for a generated Notice module).
4. Import direction: services may import domain packages; domain packages must not import services.
5. Prefer app/services for new code; add a domain package only for pure logic, strong reuse, or to break an import cycle.

Domain packages

Capability	Location	Notes
Payment status gate	app/payment	PaidResult, ApplyPaidResultStatusGate
Payment gateway drivers	app/payment/gateways/	one file per channel; payment.RegisterGateway; see Payments
Payment wiring	providers.PaymentServiceProvider	blank-import gateways; inject ResolvePaymentAmount
Payment DB apply	app/services/payment_apply.go	orchestration in services; allowlist EnabledPaymentGateways
Search engine	app/search	Engine / Resolve / drivers; must not import services
Order search adapter	app/search/orders	Document / Push / Query; loaders via SearchServiceProvider
Data scope	app/rbac	ApplyDataScope / CanAccessOwnedBy
Order filters + JSON	app/services/order_filters.go, order_json.go	same package as CRUD
Tenancy helpers	app/tenancy	hints / CacheKey / StoragePrefix
Import task center	services + controllers	no separate app/imports

When extracting a domain package later: move the module and keep the matching Provider as the blank-import / hook injection point; domain packages must not import app/services.

Dual frontend

React (html-react/) is the primary UI; Vue (html/) is the parity implementation. See Frontend parity.