Compaction-loss audit

A compaction witness for agent harnesses: pin your goal, acceptance criteria, and safety rules verbatim before the harness compacts; after compaction, get a per-span survival verdict (PRESERVED / DEGRADED / LOST, dropped text named), verbatim re-injection of what was lost, or a HALT verdict when a critical span cannot be restored — every event under an Ed25519-signed compaction receipt. Solo $9/mo · Fleet $19/mo · Per-event API $0.01/event (x402); first audit free, one time per operator.