Reference and workflow guidance for the Grok Build CLI (`grok`), including interactive and headless runs, authentication, sessions, worktrees, permissions, sandboxing, MCP servers, plugins, inspection, updates, and automation output. Invoke only when the user explicitly requests the `grok-build` skill, explicitly asks to use Grok Build CLI, or an already-selected workflow requires Grok Build; do not invoke for general coding, generic shell tasks, or other agent CLIs.