10000x · 05 — Sandbox refusal probes (live)

sandbox/260 — fn_iu_piece_split refusal branches

All 10 probe rows reported pass=t (or expected status) against the live fn_iu_piece_split:

Probe	Branch	Live result
260.1	NULL source_canonical_address	invalid_input (pass=t)
260.2	NULL review_decision_id	invalid_input (pass=t)
260.3	non-array child_specs	invalid_input (pass=t)
260.4	<2 children	invalid_input (pass=t)
260.5	missing body in a child_spec	invalid_input (pass=t)
260.6	duplicate child canonical_address	invalid_input (pass=t)
260.7	bogus source canonical	source_iu_not_found (pass=t)
260.8	RD UUID not in cutter_governance	review_decision_not_found
260.9a	DOT visibility — fn in pg_proc	pass=t
260.9b	DOT visibility — table in pg_tables	pass=t

sandbox/270 — fn_iu_piece_merge refusal branches

All 10 probe rows reported pass=t (or expected status):

Probe	Branch	Live result
270.1	NULL review_decision_id	invalid_input (pass=t)
270.2	NULL merged_spec	invalid_input (pass=t)
270.3	missing merged_spec.body (content policy)	invalid_input (pass=t)
270.4	<2 sources	invalid_input (pass=t)
270.5	duplicate source canonical_address	invalid_input (pass=t)
270.6	merged_canonical == source_canonical	invalid_input (pass=t)
270.7	bogus source list	source_iu_not_found (pass=t)
270.8	RD UUID not in cutter_governance	review_decision_not_found
270.9a	DOT visibility — fn in pg_proc	pass=t
270.9b	DOT visibility — table in pg_tables	pass=t

Transactional safety

Each sandbox is wrapped BEGIN; ... ROLLBACK; so production state is guaranteed untouched. Pre/post iu_split_set / iu_merge_set counts: 0 / 0.

Bug found and fixed mid-run

The 260.8 / 270.8 probes initially raised:

ERROR: column "id" does not exist
WHERE id = p_review_decision_id

Migrations 027 + 028 wrote WHERE id = p_review_decision_id against cutter_governance.review_decision, but the live PK column is review_decision_id. Migrations patched, re-applied (CREATE OR REPLACE is idempotent), and re-probed — all branches green. Lesson captured in 08-regression-matrix-and-lessons.md.