next.js

4385ed36 - Turbopack: Reorganize runtime files into shared/runtime directory (#89461)

Turbopack: Reorganize runtime files into shared/runtime directory (#89461) This change moves runtime code that does not use a module system and is concatenated by Rust into a dedicated `runtime/` directory so it's not confused with other code. It also codifies this in a README and instructs agents to read nearby READMEs so they enforce this convention. **This change only moves code and does not refactor any further.** Snapshot updates reflect the new file paths in the generated runtime code. **Test Plan:** CI, existing tests