Add Build Remote Agent phone pairing (gbr/1)

[LinespottingPrivate]

What

Add a short how-to so a phone running Build Remote Agent can pair to this desktop Grok Build session as a spectator.

Existing remotes stay. grok_search MCP and slash commands stay.
Build Remote Agent is a separate pairing device: the iOS/Android store app plus free MIT gbr-agent over a GitHub/HTTPS relay (gbr/1). Phone and PC never open ports to each other. No fourth pair protocol.

gbr-agent already probes companion ports :2421 / :7910 / :8787 when those UIs are running (discovery only).

Pair + attach

curl -fsSL https://grokbuildremote.com/install.sh | bash   # Windows: irm https://grokbuildremote.com/install.ps1 | iex
gbr-agent version    # need v0.6.0+
gbr-agent pair && gbr-agent run
curl -sS http://127.0.0.1:8788/health
curl -sS http://127.0.0.1:8788/v1/sessions

MCP stdio: clone https://github.com/LinespottingOrg/GrokBuildRemote-Agents and run node mcp/gbr-mcp/bin/gbr-mcp.js.

Phone is spectator + veto. Orchestration stays on this desktop agent (or a bot talking to the same Bot API).

Notes

• Independent product (Linespotting AB). Not affiliated with xAI or SpaceX.
• Docs/skill only. No product-code change. No mailbox keys.
• Host: VasiHemanth/grok-build-plugin

Website: https://grokbuildremote.com/
Agent: https://github.com/LinespottingOrg/GrokBuildRemote-Agents