04 - fn_birth_register Contract Review

Verdict

Conditionally usable for the current five targets, but not sufficiently fail-closed as a general shared contract.

Confirmed: dry-run defaults true; exempt/deferred skip; unknown/unclassified block; real writes use ON CONFLICT(entity_code) DO NOTHING.

Risks: idempotency is global on entity_code rather than collection+entity; cross-collection collision is silently treated as existing/conflict; arbitrary row JSON is accepted without source-existence proof; dry-run hardcodes duplicate_risk=0.

Required fix: explicitly block/report cross-collection collision and calculate collision risk.