ARCH — Sprint 4 (v1.0.0) defined the architecture: constitution.md with 7…

Sprint 4 (v1.0.0) defined the architecture: constitution.md with 7 non-negotiable principles, a C4 diagram, the bi-temporal SQLite model, the RunSpec YAML format, and the initial three-service Docker Compose; SQLite-over-PostgreSQL was resolved on a minimal-complexity principle.

Source: PUMA project documentation · Traceability: corpus unit ANXHN-019 · Confidence: verified-at-primary-source