fix(plugin): regenerate package-lock.json for openclaw@2026.6.1 (#4)

The plugin's package.json was bumped to openclaw ^2026.6.1 but the
lockfile still pinned 2026.5.26, so npm ci has been failing on every
push since the bump:

  Invalid: lock file's openclaw@2026.5.26 does not satisfy openclaw@2026.6.1

Re-runs npm install --package-lock-only to refresh the lockfile.
Confirmed with npm ci locally — exit 0.

Co-authored-by: Teodor Calin <teodor@vulturelabs.io>

Author: TeoSlayer