write-api-reference

Produces API reference documentation for Next.js APIs: functions, components, file conventions, directives, and config options. **Auto-activation:** User asks to write, create, or draft an API reference page. Also triggers on paths like `docs/01-app/03-api-reference/`, or keywords like "API reference", "props", "parameters", "returns", "signature". **Input sources:** Next.js source code, existing API reference pages, or user-provided specifications. **Output type:** A markdown (.mdx) API reference page with YAML frontmatter, usage example, reference section, behavior notes, and examples.