adds scripts/tests/test-hf-repos-resolve.sh: an opt-in, network-gated
check that every hf_repo / hf_repos entry in the weights registry
actually resolves on HF, not just string-matches the profile. catches
the renamed / never-existed repo class from #316 that the string-only
guard in test-model-weights-registry.sh can't see.
gated behind CLUB3090_CHECK_HF_REPOS=1 and self-skips otherwise, so the
default `for t in scripts/tests/*.sh` sweep stays offline-safe and green.
follows redirects like `hf download` does, so a rename or recase resolves
and is flagged (not failed); only a real 404 fails. gated 401/403 counts
as exists; network / rate-limit codes are reported but not counted, to
avoid spurious reds.
refs #320, #316
DeuceBucket
16271e9695