Operator answer, exact utterance: "wire tier 1 as the blocking preflight Pn"
(2026-07-26), resolving the open sequencing question. Recorded on D-137.

preflight.sh gains P5: credential matrix (D-137 tier 1), blocking, with
worst-exit aggregation, placed AHEAD of the stage-2 reminders block (now P6)
so its verdict participates in the deploy decision. Tier 1 only -- it is
offline and its findings ARE the three ruled failure classes. Tier 2 needs
--remote/--privileged and a caller-supplied --pending-stage, which do not
belong in an unattended gate; that stays an open decision.

FAIL-OPEN in my own wiring, caught by the new test: a missing creds-matrix.py
makes python3 exit 2, which `note` maps to WARN -- so deleting the gate would
have downgraded it to a warning rather than stopping the deploy. P4 already
guarded this class; P5 did not until T9 failed. Now guarded explicitly.

tests/preflight 7 -> 10: T8 a red register FAILS the deploy (blocking, not
advisory); T9 fails closed when the checker is absent; T10 the gate runs
before the reminders block.

CONSEQUENCE, not overclaimed: preflight exits 1 with P5 among the reasons,
but preflight was ALREADY exiting 1 before this change (P4: octavia-pki.yaml
absent, MAAS unreachable from the jumphost). P5 adds a fifth reason to an
already-red gate; it flipped nothing and closes no open deploy path.
Verified by stashing the change and re-running.

Gauntlet ALL GREEN (80), repo-lint 0-fail.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HvCyrwvYTTcDYnRErfMsNf