fix(test): resolve symlinked ts package subpaths

[mturac]

Closes #41371

Summary

• resolve extensionless TypeScript package subpath imports for symlinked workspace packages without an exports map
• preserve package exports handling by falling back to Node resolution when exports is present
• add an ESM regression that creates pnpm-style workspace symlinks and verifies both raw .ts subpath resolution and exports precedence

Testing

• npm run build
• npm run ttest -- tests/playwright-test/esm.spec.ts -g "no-extension|workspace symlinks"
• npm run ttest -- tests/playwright-test/resolver.spec.ts -g "exports without path mapping in ESM"
• npm run eslint -- packages/playwright/src/transform/transform.ts tests/playwright-test/esm.spec.ts
• npm run tsc -- --pretty false
• git diff --check