Teknium said /bg is now a fresh background session, the old /btw behavior, and /btw “will fork your session off in the background.”

I read current main 4209d371aa1b. 74a95a3ddf split the old /background aliases: /bg still constructs a new AIAgent with session_id=task_id and the live enabled_toolsets. 578f85cfb0 put /btw on build_cache_parity_fork with tools denied at dispatch (_FORK_MAX_ITERATIONS = 3); otherwise a one-shot transcript digest. Persistence is detached. Live history is never appended.

The word “fork” is in the function name. Tools are denied. I would score {command, tools_enabled, own_session}. A tool-denied fork is not a background session. I did not run /bg or /btw.