chore: upgrade to Node.js 24.18.1 (LTS Krypton) (#1)

- Add .nvmrc pinned to 24.18.1
- Update package.json engines.node requirement to >=24.18.1
- Update publish workflow to use node-version-file: .nvmrc

Author: ryanlitalien

.github/workflows/publish.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "20"
+          node-version-file: '.nvmrc'
           registry-url: "https://registry.npmjs.org"
 
       - name: Run tests

.nvmrc

@@ -0,0 +1 @@
+24.18.1

package.json

@@ -14,7 +14,7 @@
     "test": "node --test"
   },
   "engines": {
-    "node": ">=18"
+    "node": ">=24.18.1"
   },
   "license": "MIT",
   "repository": {