fix: configure npm auth in release workflow

setup-node registry-url creates .npmrc with auth token reference,
and NODE_AUTH_TOKEN maps the NPM_TOKEN secret for changesets publish.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -20,6 +20,7 @@ jobs:
         with:
           node-version: 20
           cache: npm
+          registry-url: https://registry.npmjs.org
 
       - name: Install dependencies
         run: npm ci
@@ -37,4 +38,4 @@ jobs:
           commit: "chore: version packages"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}