chore(deps): bump vite, plugin-react, eslint, @eslint/js majors together (#44)

Combines Dependabot #10 (plugin-react 5→6), #13 (@eslint/js 9→10),
#39 (vite 7→8), #41 (eslint 9→10). They're peer-dep coupled and
can't merge separately.

- vite ^7.3.1 → ^8.0.10
- @vitejs/plugin-react ^5.1.1 → ^6.0.1
- eslint ^9.39.3 → ^10.2.1
- @eslint/js ^9.39.3 → ^10.0.1

Build verified locally.

Author: RobThePCGuy