Query pubsub events captured by the current MCP session.

Each session subscribes to all configured robots' pubsub trees on connect and records messages in a ring buffer (capacity configurable via :bb_mcp, :event_buffer_size, default 1000). This tool returns the most recent events, optionally filtered.

Events arrive in real time so the agent can use this tool after invoking a command to inspect motion lifecycle, joint-state changes, or other pubsub traffic without polling the robot state.