feat!: migrate tests to node:test and require Node 24

Combined PR2 (test migration) + PR3 (CJS to ESM):

Test migration:
- Migrate all test files from mocha/chai to node:test + node:assert
- Use --experimental-transform-types --test-force-exit --test-timeout
- Fix browser-logs stack trace assertions (regex instead of hardcoded columns)
- Split parse5 type imports for Node 24 native type stripping
- Add import type to all type-only imports/exports for verbatimModuleSyntax compat

CJS to ESM:
- Add "type": "module" to all TypeScript packages
- Update exports to use "default" condition
- Delete index.mjs shim files
- Fix CJS interop (import.meta.resolve, createRequire, import.meta.dirname)
- Keep JSDoc packages (parse5-utils, config-loader, etc.) as CJS
- Strip ESM export keywords from browser-injected scripts
- Add .nvmrc (v24.11.1)
- Update CI workflows to Node 24

BREAKING CHANGE: Node 24+ is now required.

Assisted-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bennypowers

.changeset/browser-logs-node-test-runner.md

@@ -0,0 +1,19 @@
+---
+"@web/browser-logs": major
+---
+
+BREAKING: Migrate to Node.js native test runner
+
+- Replace Mocha with Node.js `node:test` module
+- Replace Chai with Node.js `node:assert/strict`
+- Use Node 24's native TypeScript type stripping (enabled by default)
+- Update test imports for ES modules (__dirname, require)
+- All 41 tests passing
+
+**Migration:** No API changes. Development-only breaking change.
+
+**For contributors:**
+- Tests now use `node:test` instead of Mocha
+- Use `npm run test:node` to run tests
+- Node 24+ required for development
+- TypeScript test files run directly without build step

.changeset/node-24-lts-requirement.md

@@ -0,0 +1,51 @@
+---
+"@web/browser-logs": major
+"@web/config-loader": major
+"@web/dev-server": major
+"@web/dev-server-core": major
+"@web/dev-server-esbuild": major
+"@web/dev-server-hmr": major
+"@web/dev-server-import-maps": major
+"@web/dev-server-legacy": major
+"@web/dev-server-polyfill": major
+"@web/dev-server-rollup": major
+"@web/dev-server-storybook": major
+"@web/mocks": major
+"@web/parse5-utils": major
+"@web/polyfills-loader": major
+"@web/rollup-plugin-copy": major
+"@web/rollup-plugin-html": major
+"@web/rollup-plugin-import-meta-assets": major
+"@web/rollup-plugin-polyfills-loader": major
+"@web/rollup-plugin-workbox": major
+"@web/storybook-builder": major
+"@web/storybook-framework-web-components": major
+"@web/storybook-utils": major
+"@web/test-runner": major
+"@web/test-runner-browserstack": major
+"@web/test-runner-chrome": major
+"@web/test-runner-cli": major
+"@web/test-runner-commands": major
+"@web/test-runner-core": major
+"@web/test-runner-coverage-v8": major
+"@web/test-runner-junit-reporter": major
+"@web/test-runner-mocha": major
+"@web/test-runner-module-mocking": major
+"@web/test-runner-playwright": major
+"@web/test-runner-puppeteer": major
+"@web/test-runner-saucelabs": major
+"@web/test-runner-selenium": major
+"@web/test-runner-visual-regression": major
+"@web/test-runner-webdriver": major
+---
+
+**BREAKING**: Require Node.js 24 LTS (Iron)
+
+Update minimum Node.js version from 18.0.0 to 24.0.0 across all packages. Node.js 18 reached EOL in April 2025
+
+**Migration:**
+Update your Node.js version to 24 or later:
+```bash
+nvm install 24
+nvm use 24
+```

.nvmrc

@@ -0,0 +1 @@
+v24.11.1