dot-iu-cutter v0.4 — DOT Lane Overlap Prevention GPT Mandate

Date: 2026-05-17 Authority: GPT acting on User instruction

Purpose

Prevent low-probability but high-impact overlap between DOT lanes, especially DOT-991 executor signatures and DOT-992 verifier signatures.

Binding rule

DOT_lane_overlap_prevention: required
DOT_991_executor_lane: CUT / executor / change-set attestation
DOT_992_verifier_lane: VERIFY / verifier / verify-result attestation
shared_dot_pair_signature_table: allowed_only_with_strict_lane_constraints
ambiguous_signature_rows: forbidden

Required invariants

invariants:
  - DOT_991_must_never_write_or_reference_verify_result_id
  - DOT_992_must_never_write_or_reference_change_set_id
  - DOT_991_signature_must_have_cross_reference_change_set_id_non_null
  - DOT_992_signature_must_have_cross_reference_verify_result_id_non_null
  - exactly_one_cross_reference_column_non_null_per_signature_row
  - signer_dot_id_must_match_signature_lane
  - signature_lane_must_match_reference_kind
  - no_runtime_inference_from_free_text_payload_only
  - no_magic_string_lane_mapping_without_schema_binding_test
  - tests_must_fail_if_DOT_991_and_DOT_992_are_swapped

Required code/test checks for current fix cycle

The current DOT-pair signature cross-reference fix must include tests for:

tests_required:
  - DOT_991_row_has_signer_dot_id_DOT_991
  - DOT_991_row_has_lane_executor_or_equivalent
  - DOT_991_row_has_cross_reference_change_set_id_only
  - DOT_991_row_has_no_cross_reference_verify_result_id
  - DOT_992_row_has_signer_dot_id_DOT_992
  - DOT_992_row_has_lane_verifier_or_equivalent
  - DOT_992_row_has_cross_reference_verify_result_id_only
  - DOT_992_row_has_no_cross_reference_change_set_id
  - swapped_lane_negative_test_fails_or_is_rejected
  - both_cross_refs_non_null_negative_test_fails_contract
  - both_cross_refs_null_negative_test_fails_contract

Runtime posture

runtime_posture:
  - lane_selection_explicit_not_inferred
  - lane_reference_mapping_centralized_in_schema_binding_if_nontrivial
  - no_cross_lane_fallback
  - no_auto_repair_of_mismatched_DOT_lane
  - STOP_on_lane_reference_mismatch

Current cycle effect

This mandate does not authorize schema migration or production execution. It only strengthens the ongoing code fix and tests.

schema_migration: not_authorized
production_connection: forbidden
production_secret_read: forbidden
production_CUT_VERIFY: forbidden
code_fix_scope: DOT_pair_signature_cross_reference_fix_only