The committed golangci gate now reports 0 issues, so the previous
lint_issues metric was saturated and could no longer measure progress.
Measure debt against an immutable .auto/lint.ref.yaml snapshot that adds
analyzers for genuine defects (panics, error unwrapping, dead stores,
missing enum cases, method ordering, suppression hygiene) while excluding
cosmetic churn (tagliatelle, wrapcheck). Guard enforces build, vet, tests,
the Cordis architecture gate, and anti-cheat floors: the yardstick cannot
be edited, the project gate may only be strengthened, nolint directives may
only shrink, and no test may disappear.