06 — Regression Safety

All fixtures wrapped in BEGIN; ... ROLLBACK; so nothing persists. Each fixture creates one staging_record + one cut_manifest payload + one coverage_proof payload, calls preflight or verify_mark, then rolls back.

Results matrix

#	fixture	expected	actual	PASS?
F.1	valid 2-piece law_unit manifest (parent→child, dense positions 1,2, section_type=heading/paragraph, manifest_digest 32-hex, coverage matches)	ok=true verdict=approved cut_readiness_ok=true axis_a..d=true gates e1..e7=true	exactly as expected; 0 problems	YES
F.2	single unit_kind=law_section piece	ok=false verdict=rejected axis_d_ok=false with Axis D problem	exactly as expected; 1 problem (Axis D)	YES
F.3	piece with empty content_text AND empty canonical_address	e4_title_ok=false E4 problem	exactly as expected; 1 problem (E4)	YES
F.4	piece with canonical_address = existing IU (D38-DIEU35-S8-P1)	e2_addr_ok=false address_collisions=1 E2 problem	exactly as expected; 1 problem (E2 collisions=1)	YES
F.5	piece with section_type='not_a_real_section'	e1_section_ok=false E1 problem	exactly as expected; 1 problem (E1)	YES
F.6	fn_iu_verify_mark(p_apply=true) with invalid unit_kind	ok=false verdict=rejected cut_readiness_ok=false AND lifecycle_after=rejected (NOT approved)	exactly as expected; gate prevented bad approval	YES (critical)
F.7	fn_iu_verify_mark(p_apply=false) dry-run with invalid unit_kind	rejected verdict, lifecycle remains pending_review (no mutation)	exactly as expected	YES
F.8	fn_iu_cut_preflight_validate(p_source_hash='mismatched_hash_bbb') against manifest with source_hash='expected_hash_aaa'	E0 source_hash mismatch problem	exactly as expected; 1 problem (E0)	YES

Indexed error strings (proven on live)

Axis D: unit_kind compatibility failed (total=1, missing=0, in_vocab=0) -- every piece.unit_kind must exist in dot_config vocab.unit_kind.*
E1: section_type compatibility failed (total=1, in_vocab=0) -- every piece.section_type must exist in dot_config vocab.section_type.*
E2: canonical_address collision with existing information_unit (collisions=1) -- CUT would refuse via fn_iu_classify_existing
E4: title not derivable on 1 piece(s) -- both first-line(content_text) and canonical_address are empty
E0: source_hash mismatch (expected=expected_hash_aaa, got=mismatched_hash_bbb)

"Postgres text[] || bare literal" lesson re-applied

fn_iu_cut_preflight_validate accumulates text[] problems exclusively via the ARRAY['...'] form (e.g. v_problems := v_problems || ARRAY['Axis D: ...'];), never via v_problems || 'bare literal'. This avoids the operator-resolution gotcha that masked a contract gap in earlier verify_mark work. See [[feedback-postgres-text-array-concat-bare-literal-cast-gotcha]].

State invariants

invariant	pre-Phase-F	post-Phase-F
information_unit count	200	200
iu_vector_sync_point count	152	152
iu_staging_record count	10	10
dieu39_iu_count	0	0
manifest 9fa4685e lifecycle	approved	approved
cut_request 146f1520 status	mark_verified	mark_verified
cut_request 146f1520.cut_run_id	NULL	NULL
gate queue.job_substrate.enabled	false	false
gate iu_core.composer_enabled	false	false
gate queue.heartbeat.enabled	true	true
gate queue.dlq.replay_enabled	false	false
production_documents	absent	absent
pg_cron	absent	absent

Forbiddens re-checked against this phase

1. No pg_cron. 2. No worker process started. 3. No event_outbox mutation. 4. No Qdrant. 5. No production_documents write. 6. No runtime.phase flip. 7. No CUT. 8. No VERIFY_CUT. 9. No COMPLETE. 10. No new cut_request. 11. No silent vocab widening. 12. No silent mapping. 13. No alias contract change. 14. No manual manifest patch. 15. No --no-verify / hook-skip.

Plug into broader pipeline

These fixtures cover happy path + 6 failure modes. A 9th fixture (heading→paragraph parent_local_id pointing outside manifest) would exercise Axis C explicitly; it is logically covered by the existing pre-mig fn_iu_verify_mark Axis C test in the parent root-cause pack and is regression-stable under the new delegation.