AGP Supervised Runtime Envelope

As of 2026-04-18, the promoted cross-host runtime pair is the supervised `9430 + 9434` path on `mac5`. Both are now supervised by `runtime/supervise_agp_server_v1.sh`, and the client transport path is hardened by reconnect and retry logic in `runtime/run_cross_host_packet_replay_v1.py`. This matters because the earlier frontier was not limited by representational quality alone. It was limited by daemon lifetime and process churn. Once the runtime was supervised and the client learned how to survive restarts, the architecture crossed into a more credible operating regime. The main supervised sweep over remote margin thresholds on the held-out Thunder validation slice produced six evaluated operating points. At `0.03`, the system executed `13` steps and reached `0.6154` top-1 teacher match with mean KL `1.0492` and mean RTT `43.66ms`. This is too permissive. It buys coverage, but not enough quality or latency advantage to justify promotion.