The rule (CLAUDE.md, operator ruling 2026-09-13): until the Update button takes a verified backup
as its precondition, no template may move a mariadb:/postgres: image across a major version. Four
MariaDB and eleven PostgreSQL services; the gate finds them by image name, not by a list.
scripts/check-engine-major.py — fast (git reads only), diffs each changed template's per-service
image: line between the two ends of the push range, refuses a major move naming the rule and its
expiry (R-448). Fourth row of catalog_gates.py; .githooks/pre-push now hands the push range
through as --range=<remote sha>..<local sha>.
HONEST LIMIT: it needs a parent commit and CI fetches at --depth 1 (the R-452 gap, not re-filed),
so on a shallow clone the runner SKIPS it out loud instead of reddening every CI push. The hook,
which has the full clone, is where it bites.
Red-proof (scripts/test_gate_decoys.py, 7 cases, all seen to judge correctly): mariadb 11.6->12.3
REFUSED, postgres 16->17 REFUSED, mariadb:lts INCONCLUSIVE; 11.6->11.8 PASSES; the major moving
only in a comment / kimai's serverVersion env / README / the app's own image PASSES. COVERS literal
registered for felhom.eu's decoy_coverage_gate (which now reads 1 covered, 3 exempt, 0 unaccounted).
test_catalog_gates.py pins the four-gate table and the announced shallow-clone skip.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS
The workspace root is already documented (workspace-CLAUDE.md, the workspace-root
CLAUDE.md 'stay inside it') and work drifted into a home directory anyway. A rule
that has failed once as a reminder is not fixed by writing it down again, so it is
now asserted where it can bite.
A push is the right trigger: throwaway clones under /tmp for probes and red-proofs
never push, so nothing legitimate breaks. Symlinks are resolved on both sides; an
absent workspace root SKIPS the check rather than failing it, so this cannot brick
a legitimate clone on another machine. The only bypass is the documented
--no-verify, whose use is already reportable.
Identical in all four repos.
--fast selects only gates that touch no network and no container runtime: gate 1
(check-image-pins) runs, image-resolvable and volume-persistence do NOT. Default behaviour with
no flag is unchanged. The skip is ANNOUNCED with the reason and with what still owes a periodic
run — a silently narrowed run reads as 'covered everything' when it did not.
Why the runtime gates are never in a hook: a push that pulls images and starts containers gets
bypassed within a week, and the bypass becomes the habit. They stay deliberate periodic runs at
the start of a catalog campaign, before a publish train, and when a template's volumes: block or
image tag changes — on a scratch host, never a customer box.
.githooks/pre-push runs catalog_gates.py --fast and refuses the push. Per-clone and
--no-verify-able, both stated in the hook itself.
test_catalog_gates.py pins --fast's CONTENT, not just its exit code: the runtime gates must not
run, the skip must be announced, and the no-flag path must still select all three. Red-proofed:
an inert run_gate turns it red.
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