Add Build Remote Agent phone pairing (gbr/1)

[LinespottingPrivate]

Add a Build Remote Agent pairing adapter so a phone can spectate this desktop session.

Protocol gbr/1 (unchanged). Phone is spectator + veto, not orchestrator.

Install + pair

curl -fsSL https://grokbuildremote.com/install.sh | bash
gbr-agent version   # need v0.6.0+
gbr-agent pair && gbr-agent run

Phone: open Build Remote Agent → scan the QR or type the printed 8-char code.

Attach (only these)

• HTTP Bot API: http://127.0.0.1:8788 after gbr-agent run
• MCP stdio: node …/gbr-mcp/bin/gbr-mcp.js (clone GrokBuildRemote-Agents, npm install in mcp/gbr-mcp)

curl -sS http://127.0.0.1:8788/health
curl -sS http://127.0.0.1:8788/v1/sessions

Independent product by Linespotting AB. Not affiliated with xAI or SpaceX.

Do not commit mailbox keys. Phone Settings → Bot API is the only place a relay key is copied.