ci: switch release to npm Trusted Publisher (OIDC, environment: release), drop NPM_TOKEN

.github/workflows/release.yml

@@ -11,6 +11,7 @@ permissions:
 jobs:
   publish:
     runs-on: ubuntu-latest
+    environment: release # must match the npm Trusted Publisher config
     steps:
       - uses: actions/checkout@v4
       - uses: pnpm/action-setup@v4
@@ -35,7 +36,9 @@ jobs:
             echo "skip=false" >> "$GITHUB_OUTPUT"
           fi
       # prepublishOnly runs typecheck + tests + build as the gate
+      # Auth via npm Trusted Publisher (OIDC) - no token needed.
+      # Requires npm >= 11.5; Node 22 ships older, so upgrade npm first.
       - if: steps.check.outputs.skip == 'false'
-        run: npm publish --access public --provenance
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: |
+          npm install -g npm@latest
+          npm publish --access public --provenance