Legacy environment/PPO bridge

This page documents the older single-gpu-online-distillation-v1 artifact bridge. It is retained for migration and historical reproducibility; it is not miniVERL's current verl-style OPD runtime.

The legacy bridge converts validated environment data to Parquet and emits a PPO/reward integration scaffold for official verl v0.8.0 at 7aed6b23. Because teacher identity, reward semantics, base snapshots and user mappings are not fully determined, a new legacy bundle stays fail-closed:

reward_implementation_complete: false
launchable: false
distributed_execution_tested: false
algorithm_semantic_parity: false

miniVERL-defined compatibility Level 3 refers only to bundle structure, hashes and pinned parse/load smoke. It is not generic verl compatibility and does not mean a Ray/FSDP/vLLM job ran. The reward scaffold is untrusted input; doctor statically inspects it by default and executes it only after an explicit trust opt-in.

Existing legacy commands and artifacts remain readable. New users should use the current local OPD runtime and current scale-out contract, which preserve pure OPD intent and do not generate a reward scaffold.

For the complete historical security and artifact checks, see the archived combined bridge reference.