Module supervisor 

The AI supervisor: an idle tokio task owning the provider child process, the ACP Connection, and the active SessionId (AI-1b).

Agent conversation output (message/thought chunks, tool calls) folds into the structured ConversationStore (AU‑1); trace (session lifecycle, handshake, errors) flows into the AiLogger’s per-process rings – never into *messages*, never through tracing::info!. AiClientHandle::spawn is the crate’s entry point: it starts this task and returns the clone-able, non-blocking handle the editor thread talks to.