Python CLI tool for hierarchical multi-agent communication.
SQLite-backed (WAL mode), agent identity via BTMSG_AGENT_ID env var.
Features:
- inbox/read/send/reply — message CRUD with read tracking
- contacts — role-based communication hierarchy enforcement
- history — per-agent conversation view
- status — all agents with tier/role/model/unread counts
- register/allow — agent and contact management
- notify — single-line notification for agent injection
- Short ID prefix matching for convenience
Also: change default Claude model to opus-4-6
