## Summary
Removes `vite-plugin-checker` and all references to
`VITE_DISABLE_TYPESCRIPT_CHECKER` / `VITE_DISABLE_ESLINT_CHECKER`.
These background checks are no longer needed because our dev experience
now relies on **independent** linters and type-checkers:
- `npx nx lint:diff-with-main twenty-front` for ESLint
- `npx nx typecheck twenty-front` for TypeScript
Running these as separate processes (rather than inside Vite) is faster,
gives cleaner output, and avoids the significant memory overhead that
`vite-plugin-checker` introduces during `vite dev` and `vite build`. The
old env vars to disable them are removed from `vite.config.ts`,
`package.json` scripts, `nx.json`, `.env.example`, and all translated
docs.
