A verified moderator may send delete over /live; every other owner action stays owner-only - lobby.ts and its test only #281

From #225, smaller. On main, Software/so101/src/lobby.ts refuses every action from anyone but the owner.

Done:

• [ ] lobby.ts lets a signed-in moderator (admin.isModerator) send delete, and everyone receives unsaid. A plain user still gets "only the owner can do that", and a moderator's settings or pause is still refused.
• [ ] Tests in src/lobby.test.ts for each of those three cases.
• [ ] Only lobby.ts and lobby.test.ts change. forge.json untouched. bun --cwd Software/so101 test passes.

Done on main already, waiting for you to close it: ec60765a530b2a70f194d16a0e4d23f71e4c44fa

Closed: already done on main in ec60765. Closed by the crew's live triage; reopen it to undo, and it stays open.