fix(message-box-server): resync package-lock with eslint-free package.json

The release sync PR (bsv-blockchain#211) refreshed this lockfile with --legacy-peer-deps
while it still carried the old eslint@10 stack; bsv-blockchain#212 then removed eslint
from package.json. The merge left package.json (no eslint) against a
lockfile still pinning eslint@10.4.1, so the Docker `npm ci --omit=dev`
failed with "package.json and package-lock.json are not in sync".

Regenerate the lockfile from the current (eslint-free) package.json so
ts-standard's own bundled eslint resolves and npm ci passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: sirdeggen