Architecture Decision Records

ADRs capture significant, hard-to-reverse architectural decisions. Each ADR is immutable once accepted; a later decision that changes it is recorded as a new ADR that supersedes the old one. ADRs cite the requirement IDs in PRODUCT.md they implement or change.

ADR	Title	Status
ADR-0001	Typed Facade + Sink back-end with a stable, versioned Record schema	Accepted

Writing a new ADR

Copy the structure of ADR-0001: Context (the problem and the options weighed), Decision (what we chose), Consequences (positive, negative, follow-ups). Reference affected PRODUCT.md requirement IDs. Number ADRs sequentially.