adds an optional `revision:` key per weights variant. weights.py emits
WEIGHT_REVISION; setup.sh threads it into `hf download --revision` and
pins the post-download sha-verify etag lookup to the same revision, so a
stale pin can't false-fail against a newer HEAD. preflight's manual hint
mirrors the flag. unset = track HEAD, so behavior is unchanged for every
current entry (nothing sets revision: today).
this is the weights half of #316: upstream quant repos re-quant
silently, and we had no lever to pin the bytes a BENCHMARKS row was
measured against. engine images already pin; weights didn't. mechanism
only, no real entry is pinned in this PR (that's a per-entry,
rig-validated call that's yours to make).
refs #319, #316
DeuceBucket
6be52294c8