Builtin curl in default prep has no retry/resume: an interrupted 3.7 GB
download restarts from zero and leaves a partial file that prep reuses
silently. Custom pbuild::prep resumes with wget --continue and gates the
build on gzip -t, so a truncated tarball can neither be reused nor
require a full re-download. urls: dropped from config.yaml (unused with
custom prep); install untars straight from the distfiles cache instead
of a pointless 3.7 GB copy via SRC_DIR.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>