The previous per-day cache (iso_YYYY-MM-DD) forced a fresh ~6GB download
on the first build of every day. Different channels (stable/edge/rc)
HAVE different package sets and shouldn't share a cache, but different
DAYS within a channel don't, so keying by channel gives us a stable
cache that persists indefinitely.
omarchy* packages always rebuild fresh inside the container regardless:
build-omarchy-packages.sh nukes /tmp/omarchy-pkg-build at the start
and the final mv overwrites the cached .pkg.tar.zst (pkgver is constant).
--no-cache still bypasses the mount entirely for a clean-slate run.
Ryan Hughes
874e6cd24d