A production rollout exposes a contract mismatch between the UI boundary and the owning service. The affected area is BFF contract.
Repair the BFF contract command handling implementation so it accepts first operations, recognizes safe repeats, and rejects key reuse with a different payload.
Evidence
- Affected surface: Full-stack frontend focus / BFF contract.
- Observed failure family: enforce idempotent operations.
- Scope policy: tenantId must equal tenant-primary.