S1 outcome — Remove the snapshot mutation exception

State: resolved 2026-08-23.

Outcome

ADR 072 superseded ADR 045's field placement instead of implementing this plan's one-field exception. The tracked ingest now owns durable genre. A local snapshot may contain a provisional capture-time genre, but ingestion records its closer-reading classification on the report and never edits the snapshot.

This is a stronger boundary than the planned captured-content envelope: snapshots are whole-file immutable after capture, and snapshot_sha256 covers the exact bytes that grounded the ingest. The source collection, both source types, and cp-skill-ingest agree that snapshotting may create the ignored reading copy while ingestion writes only the tracked report.

Acceptance evidence

• The ingest schema requires genre and snapshot_sha256; the snapshot schema makes genre optional.
• cp-skill-ingest copies no snapshot genre, asks the drafting worker to set genre after reading, and verifies that the snapshot checksum is unchanged across the handoff.
• Exact recapture, checksum mismatch, and absent-material behavior are covered by the snapshot resolver tests without any ingest or snapshot rewrite.
• I3 retains one follow-through obligation: its future installed sources template must project this resolved contract.