feat(agents): add Grok Build as a first-class ACP runtime

[daniel-farina]

Summary

Buzz Desktop's managed agent runtime catalog supports Goose, Claude Code, Codex, and Buzz Agent, but Grok Build is missing even though it already speaks ACP natively over stdio:

grok agent stdio

Users who want Grok-backed agents must configure a custom harness command instead of selecting Grok from Agent runtimes / onboarding.

Why

• Grok Build ships a stable ACP server (grok agent stdio) — no separate *-acp npm adapter is required (same class of integration as Goose's goose acp / Cursor's native ACP path).
• Install path is well-known (curl -fsSL https://x.ai/cli/install.sh | bash, binary under ~/.grok/bin).
• Without catalog registration, Desktop cannot discover, install-hint, or process-sweep Grok the way it does other runtimes.

Proposed solution

Register Grok Build in KNOWN_ACP_RUNTIMES with:

Field	Value
id	grok
label	Grok Build
commands	grok
Default args	agent --always-approve stdio
PATH discovery	include ~/.grok/bin
Skills	.grok/skills
Auth hint	grok login or XAI_API_KEY

Also wire onboarding visibility, docs (buzz-acp README / TESTING), and unit tests for arg normalization.

Acceptance criteria

• Grok Build appears under Desktop → Agent runtimes when grok is on PATH
• Creating/starting a managed agent with runtime=Grok spawns grok agent … stdio via buzz-acp
• buzz-acp models with BUZZ_ACP_AGENT_COMMAND=grok completes an ACP handshake
• Docs describe the Grok path alongside Goose/Claude/Codex

Related

• Pattern references: Pi ACP (feat(agents): add Pi ACP runtime support #2257), Cursor ACP (feat(desktop): register Cursor as a native ACP runtime #1683)
• Grok ACP docs: grok agent stdio / Agent Client Protocol mode

[daniel-farina]

Solution

Implemented in #2344:

#2344

That PR registers Grok Build in the managed ACP catalog (id: grok), defaulting to:

grok agent --always-approve stdio

It also adds ~/.grok/bin discovery, onboarding visibility, docs, and unit tests. Live-validated with buzz-acp models and a channel @mention E2E against a hosted relay.

Please review/merge #2344 to close this.