PublishedHistory

An append-only store of published schema snapshots (design §5). Each released version's schema is recorded once, under <version>.snapshot, and never mutated — that immutable record is what lets com.chrisjenx.serialkompat.core.TransitiveCompatibility verify the current schema against every version persisted data might have been written with, not just the latest.

Each entry is a small @history header (version + record time) followed by a blank line and the canonical SnapshotFormat text. The header key is distinct from any block SnapshotFormat emits, so it never collides with schema content.

Reads are validated and fail-closed and writes are atomic: a corrupt or half-written entry (e.g. a CI job killed mid-write) throws on load rather than being silently skipped — under-reporting a transitive break would defeat the gate.