next.js

30421ba1 - Mark .agents/skills as internal so external `npx skills add` hides them (#93856)

Mark .agents/skills as internal so external `npx skills add` hides them (#93856) Adds `metadata.internal: true` to all 12 `.agents/skills/*/SKILL.md` files so external `npx skills add /path/to/next.js` no longer lists Next.js framework-dev skills — only `next-compile` remains visible. <!-- NEXT_JS_LLM_PR -->