Migrate Solid 1.x to 2.0

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

1. Establish source and target. Read the installed version/lockfile and the requested target. Apply this workflow when converting 1.x to major 2; keep ordinary maintenance on its existing major. Match runtime, web renderer, and compiler packages. Installed target typings outrank reference prose.
2. Read migration-map. Update imports, JSX config, and renamed APIs first. Then rewrite effects, async resources, store setters, and lifecycle by intent using the map's examples.
3. Check semantics at each changed call site. Track reads in JSX/compute; perform writes in imperative callbacks; check list callback shapes, cleanup, read-after-write ordering, and pending/saving state separately.
4. Validate. Typecheck against the target, run project tests, and exercise changed UI paths in dev. Repair diagnostics at their source. Check async loading/error/retry, disposal, and hydration when those paths changed.