briefing

Author and migrate Claude Code subagents that use the `briefing` plugin — the PreToolUse hook that pre-loads declared skills into the agent's context at spawn time. Use this skill when adding `briefing.skills` to an agent's frontmatter, when refactoring an existing agent away from "MANDATORY: load skill X first" prose, or when debugging why a declared skill is not being resolved.

Trivial skill used to verify that briefing pre-loads it into a subagent's context.