The sweep's rating feature was wired against REINS' single 'pending'
capture (one slot per key, overwritten by whatever generates next),
which meant only the MOST RECENT result in a whole batch could ever be
rated -- the opposite of what batch training actually does: rate every
result you generated, independently, in any order.
New h3_repr_capture_slot sampler input (blank by default = unchanged
ordinary one-at-a-time flow) saves a run's capture under an explicit
slot instead of the single pending. New h3_repr_steering.save_capture_slot
/ commit_slot / discard_slot mirror save_pending/commit but keyed, so a
whole batch stays independently rateable the same way batch_training.py's
per-item .cond.pt files already do for value-function training.
New server routes commit/discard a slot directly -- no extra generation
needed, unlike the old 'fire another render with rating attached'
workaround that existed only because of the single-slot limitation.
Every gallery card is now rateable (Like/Dislike/Skip), not just the
last one.