### Added

- Add dedicated ESM, CommonJS, Node.js, and browser distribution entry points.
- Add streaming support to the native Node.js SHA-256, SHA-224, and HMAC implementations.
- Add distribution contract tests and real browser Web Worker tests with Playwright.
- Add Node.js 16, 18, 20, 22, and 24 runtime tests against the packed npm artifact.

### Changed
- Refactor the implementation into environment-independent core and Node.js modules.
- Use the native Node.js `crypto` implementation for hashing and HMAC.
- Load the package version automatically when generating distribution banners.
- Export unminified ESM source directly and build only CommonJS and browser/minified distributions.
- Replace `expect.js`, NYC, Tiny Worker, and UglifyJS with Node.js assert, c8, Playwright, and Rollup/Terser.
- Build automatically before `npm pack` and `npm publish`.
- Throw error if update after finalize

### Removed
- Remove runtime CommonJS, AMD, Node.js, Web Worker, and ArrayBuffer environment switches from the core implementation.
- Remove legacy environment flags and obsolete compatibility polyfills.
- Remove the old generated `sha256.mjs` and `sha256.node.mjs` entry points.

src/umd.mjs

@@ -0,0 +1,14 @@
+import sha256, { sha224 } from './core.mjs';
+
+const root =
+  typeof globalThis === 'object' ? globalThis :
+  typeof self === 'object' ? self :
+  typeof window === 'object' ? window :
+  typeof global === 'object' ? global :
+  undefined;
+
+if (root) {
+  root.sha224 = sha224;
+}
+
+export default sha256;