Review SolidJS 2.0

Reference target: solid-js@2.0.0-rc.8 and @solidjs/web@2.0.0-rc.8.

Establish scope

Read the installed solid-js version and review the requested diff/files. Apply this checklist to major 2. Keep v1 reviews on their v1 contract. Published target typings outrank examples and prerelease documentation.

Check behavior