Adds the VoiceClaw-compatible realtime brain WebSocket endpoint backed by Gemini Live, with owner-auth gating, async OpenClaw tool handoff, docs, and lifecycle tests.
Maintainer fixup: terminal upstream errors now send the error, emit session.ended while the client socket is still open, then close the client-facing socket.
Co-authored-by: Michael Yagudaev <1386966+yagudaev@users.noreply.github.com>