Next.js adapter (App Router + Pages Router)

[PAMulligan]

Goal

First-class Next.js integration so embedders can drop Claudius into App Router or Pages Router projects without manually wiring the worker route and the client component.

Acceptance criteria

• @pmds/claudius-next package with <Claudius /> component
• Server route handler factory for /api/claudius/*
• Streaming responses verified end-to-end
• Example app in examples/next-app-router
• Example app in examples/next-pages-router
• README quickstart section

Milestone

v1.2.0