Scaffold, review, upgrade, or diagnose agent skills against best-practice frontmatter, progressive disclosure, token-aware structure, and the agent-skills.git symlink + inventory wiring. Modes: `scaffold` (default — new skill), `review` (audit existing skill), `upgrade` (split a single-file skill in
Scaffold, review, upgrade, or diagnose agent skills against best-practice frontmatter, progressive disclosure, token-aware structure, and the agent-skills.git symlink + inventory wiring. Modes: `scaffold` (default — new skill), `review` (audit existing skill), `upgrade` (split a single-file skill into multi-file), `diagnose` (retrospective failure analysis that emits a confidence-gated unified dif