Needle scored ~chance on the golden set and never gated alerts, so drop the
sidecar, proxy handlers, UI buttons, k8s container and build step. The labelled
eval sets move to cmd/triage-eval/data.
nginx 4xx (registry 401 challenges, /oauth2/auth, scanner 405s) is now dropped
in FilterActionable instead of only being discounted, so it cannot ride along
with a real 5xx. nginx 5xx still alerts.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>