feat: [BREAKING] Set minimum Node.js to 20+ (#376)

Co-authored-by: Claude <[email protected]>

Author: scottlovegrove

package.json

@@ -10,7 +10,7 @@
     "types": "dist/index.d.ts",
     "sideEffects": false,
     "engines": {
-        "node": ">=8.0.0"
+        "node": ">=20.0.0"
     },
     "scripts": {
         "clean": "rimraf dist",