Next.js locale routing — monorepo (shared package)

The same locale-routing behaviour as nextjs-locale-standalone, but the engine lives in one workspace package (i18n-routing) that every app imports, so detection, the cookie name, and the provider/hooks stay identical across apps. Read that sibling skill for the behaviour spec; this skill is about the package + wiring. Copy-paste files are in templates/.

The behaviour (shared with the standalone skill)