ci: skip npm publish when the version is already on the registry

Makes the release job idempotent: if the package@version is already
published (a manual bootstrap publish, or a re-run of a released tag), skip
npm publish and still create the GitHub release instead of failing on
"cannot publish over existing version".

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lj241sZMvCV2wAuH1A65Fm

Author: ymansurozer

.github/workflows/release.yml

@@ -27,7 +27,17 @@ jobs:
       - run: pnpm smoke
       # OIDC trusted publishing (tokenless) requires npm >= 11.5.1
       - run: npm install -g npm@latest
-      - run: npm publish --provenance --access public
+      # Idempotent: skip when this exact version is already on the registry (e.g. a manual
+      # bootstrap publish, or a re-run of a released tag) so the tag still produces the GitHub
+      # release below instead of failing on "cannot publish over existing version".
+      - run: |
+          NAME=$(node -p "require('./package.json').name")
+          VERSION=$(node -p "require('./package.json').version")
+          if npm view "$NAME@$VERSION" version >/dev/null 2>&1; then
+            echo "$NAME@$VERSION already published — skipping npm publish."
+          else
+            npm publish --provenance --access public
+          fi
       - run: npx changelogen@latest github release --token "$GITHUB_TOKEN"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}