Admins can now run 'rs gain list|grant <vip>|revoke <vip>' from web chat or
Discord. Grant matches only against the verified list and revoke only
against current holders, so a nickname shared with an unverified visitor
reports not-found rather than resolving to someone ineligible. The action
joins the moderation set so lockdown narrows it to lockdown admins.
Also extracts the ceiling math into audioLevelsService/gainMath.js and
covers both it and the command with node:test suites.
Co-Authored-By: Claude <noreply@anthropic.com>
