a_forged_lens_weights_row_fails_replay re-sealed only the commit digest, so
its all-zero forgery was refused by the resulting-state-digest mismatch and
still passed with draws() weakened. Each forgery now re-seals the whole store:
the head takes the effect's weights, its state digest is recomputed, the
commit's resulting state digest and digest follow, and the head's last commit
digest names the re-sealed commit; every seal is asserted consistent.
A drawing control re-sealed the same way replays, so no digest is left to
answer. The caller forgeries assert an ownership refusal and the all-zero
forgery asserts a draw-rule refusal.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>