SSR dev server fails with "module is not defined" for CJS dependencies (void-elements, highlight.js, etc.)

## Description

When migrating a Next.js Pages Router project to vinext, `vinext dev` fails with `500 Internal Server Error` because Vite 8's `ESModulesEvaluator` cannot handle CommonJS dependencies that use `module.exports`.

## Reproduction

1. A Next.js project with common CJS dependencies (e.g. `react-i18next` → `html-parse-stringify` → `void-elements`, or `highlight.js`)
2. Run `npx vinext init` then `npx vinext dev`
3. Visit `http://localhost:3000/`

## Error

Error when evaluating SSR module /src/pages/index.tsx: module is not defined
at eval (node_modules/void-elements/index.js:8:1)
at ESModulesEvaluator.runInlinedModule (vite/dist/node/module-runner.js:988:161)

ReferenceError: module is not defined
at node_modules/void-elements/index.js:6:1

After externaling `void-elements`, the same error occurs for `highlight.js/lib/core.js`, and so on for other CJS-only packages.

## Attempted workarounds

| Config | Result |
|---|---|
| `ssr.noExternal: ['void-elements', ...]` | Same error, CJS not transformed |
| `ssr.noExternal: true` | Same error |
| `ssr.external: ['void-elements', ...]` | Fixes that package, but next CJS dep fails (whack-a-mole) |
| `ssr.external: true` | Even `react` itself gets externalized and fails |
| `ssr.external: [/node_modules/]` | Vite 8 rejects RegExp: `Value is non of these types True, Array` |

## Root cause

Vite 8's `ESModulesEvaluator` (used by `SSRCompatModuleRunner`) runs module code in strict ESM scope where `module` is not defined. CJS packages that use `module.exports = ...` fail immediately. Vite's CJS→ESM transform doesn't seem to kick in
for these dependencies during SSR dev.

## Environment

- Node.js: v22.22.1
- vinext: 0.0.31
- Vite: 8.0.1
- Package manager: pnpm 10.32.1
- OS: macOS (darwin-arm64)

## Affected packages (partial list)

- `void-elements` (via `react-i18next` → `html-parse-stringify`)
- `highlight.js`
- `react` itself (`react/index.js` uses `module.exports`)
- Many others — most npm packages still ship CJS

## Expected behavior

vinext should handle CJS dependencies transparently in SSR dev mode, similar to how Next.js webpack does.