pi0.5 AXIS v2.0 fine-tune (v2d)

Canonical parent: Fisher-Wang/pi05-axis-v0.2-all30-74p67 @ 521a0741c01ee7908b5794bb2ae6933d3dc04745. Full-model fine-tune on our own AXIS v2.0 replay renders and retargeted rollouts. No other miner's weights.

Local score 0.6100 (366/600), policy seed 20260907, randomization seed 20260928.