Core Changes

• Turbopack: Allow turbopack-node backend to be swapped at runtime using an experimental config option: #90671
• Turbopack: Revert default loader runtime backend to child processes: #90675

Misc Changes

• turbo-persistence: streaming SST writer for reduced memory usage: #90617
• Add custom cleanup script support for deploy tests: #90696

Credits

Huge thanks to @lukesandberg, @bgw, and @ijjk for helping!