ADR-004: Backend scope and inherited engineering rules

Status: Adopted for planning. Date: 2026-09-28. Scope: planned platform; implementation evidence required by roadmap gates.

Context

The imported app is offline and generic rules demand tenants/auth on every request and events-only interaction. The user explicitly requires backend/infra before Android improvement.

Decision

P01–P09 backend/infra, G09 gates Android work. Public reads are anonymous/cacheable where inputs are nonsensitive; contributor proof on writes/owner reads; restricted admin. No tenant concept. Explicit application interfaces allowed; domain unit tests pure, real DB integration tests required. Business append-only rules permit legally required privacy deletion.

Alternatives

Apply generic tenant/auth rules literally; start Android and backend together; replace old modules.

Consequences

Avoids needless identity/tenant coupling and user-scope violations. Current Android behavior is preserved; Kotlin fixture implementation waits until P10. Old stack/architecture rules govern Android only; new backend docs govern Go.

Validation and follow-up

Use the owning tasks in ROADMAP, specifications in docs index and decision log. Record tested policy/tool versions before marking a release gate complete.