feat(vite): support nodeIntegration renderer builds

[rafael81]

Refs #3961

Summary

• add a nodeIntegration option to @electron-forge/plugin-vite renderer entries
• when enabled, externalize Electron/Node built-ins for renderer builds and resolve packages with Node-oriented conditions/main fields
• document the new renderer option in the Vite plugin README
• add ViteConfig coverage for the default renderer path and the new nodeIntegration: true path

Validation

$ npm exec --yes @yarnpkg/cli-dist@4.10.3 -- prettier --write packages/plugin/vite/src/Config.ts packages/plugin/vite/src/config/vite.renderer.config.ts packages/plugin/vite/spec/ViteConfig.spec.ts packages/plugin/vite/README.md --experimental-cli
# passed

$ npm exec --yes @yarnpkg/cli-dist@4.10.3 -- vitest run --project fast packages/plugin/vite/spec/ViteConfig.spec.ts
Test Files  1 passed (1)
Tests  4 passed (4)

$ npm exec --yes @yarnpkg/cli-dist@4.10.3 -- tsc -b packages/plugin/vite
# passed

This PR was prepared with AI assistance and manually reviewed before submission.