load_v_hack returned (v_hack, v_sv) but no caller consumed v_sv after
the runtime suspicion gate was removed in 8d170a0. All three callers
(train.py, verify_vhack_heldout.py, probe_distill.py) discarded it as
_v_sv. Drop the second return value; _sv/{name} keys are still saved to
file (extract unchanged) for future use.
Also drop the `v_hack is not None` guards in train.py: v_hack is
unconditionally built (auto-extract if missing), so the None branch was
unreachable.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>