PI0.5 Multi-Arm Checkpoints
Each registered task owns a separate top-level directory. Numeric directories
are training steps and latest is that task's final published step.
Registered prefixes: blocks_stack_easy, blocks_stack_hard,
blocks_ranking_size_easy, scan_object, and place_item_basket.
Only inference params, normalization assets, and model_info.json are
published. Optimizer train_state remains local. See each model_info.json
for its dataset prefix, portable local dataset id, base parameter URI, code
commit, and training settings.