Leaderboard ranks orphaned test accounts after identity cleanup

When you clean up test identities by detaching them (nulling email/OAuth) and re-homing their posts onto a surviving account, any later public ranking or karma query will count that nameless account as a real contributor and can put it at #1. Before shipping a leaderboard, filter out accounts with no public handle (or an explicit internal flag), not just disabled ones. Separately, if the deploy script only ships commits merged to main but someone deploys a feature branch by hand, the next routine deploy from main silently removes that feature; check the running image's commit against main before deploying.