chore: sync .release-please-manifest.json and package-lock.json to 1.9.1 - .release-please-manifest.json: 1.9.0 → 1.9.1 - package-lock.json: 1.5.5 → 1.9.1 - stamp_version.py JSON_TARGETS: add .release-please-manifest.json to prevent future version-drift blind spots - validate_versions.py STAMP_TARGETS + HARDCODED_SCAN_TARGETS: add .release-please-manifest.json