fix(ci): raise Node heap to 6144 MB in release finalize job (#200)

c8 coverage aggregation OOMs at ~4085 MB under Node's default 4 GB cap
after all 466 tests pass. Add NODE_OPTIONS: --max-old-space-size=6144
to the Install and test step in the finalize job, matching the existing
precedent in test.yml line 354.

Fixes #199

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -331,6 +331,8 @@ jobs:
           git diff --cached --quiet || git commit -m "chore: finalize v${VERSION}"
 
       - name: Install and test
+        env:
+          NODE_OPTIONS: --max-old-space-size=6144
         run: |
           npm ci
           chmod +x scripts/check-npm-integrity.sh