Backward compatible; existing modes unchanged for existing callers.
- apt: also rewrites deb.debian.org/debian, deb.debian.org/debian-security and
security.debian.org to <cache>/debian and <cache>/debian-security; the
listing no longer fails under pipefail when /etc/apt/sources.list is absent
(Debian 13 images).
- rpm: rewrites rpm.nodesource.com repos to <cache>/nodesource (gpgcheck=1;
NodeSource does not sign repomd).
- new `nodesource MAJOR`: writes the nodesource-nodejs repo itself with the
committed signing key (replaces curl setup_N.x | bash).
- new `go-env`: prints GOPROXY=<cache>/goproxy|https://proxy.golang.org|direct
plus SSL_CERT_FILE for the RUN; go.sum + sum.golang.org still verify.
- release-install: EL9 or EL10 picked from rpm %rhel; adds RPM-GPG-KEY-EPEL-9.
- PKG_CACHE is regex-validated.
Tested through the cache on a throwaway runner CT (pve vmbr2): EL9+EPEL9,
NodeSource 22 on EL10, Debian trixie apt, golang:1.25 apt + go-env; restore
left no cache reference in each case.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>