ADR-0002: Versioned preservation archive (first/latest/milestones + checksums)

• Status: Accepted · Date: 2026-05-30

Context

The founding concept and all authored documents must be preserved verbatim and verifiably, beyond what casual git use guarantees.

Decision

Keep, per document, an immutable first, a current latest, and named milestone snapshots under archive/documents/<doc>/, each SHA-256-checksummed in MANIFEST.md. The Archivist owns it; docs/concept.md is protected.

Consequences

• Drift is detectable; integrity is verifiable on every session open/close.
• Manifest upkeep is a known cost — mitigated by scripts/archive-manifest.sh.
• Whole-repo milestones are captured as git tags (see SPECIFICATION.md §4).