Phase 10: team buzzers

Each team gets a buzzer link (/b/[token]); a game opts in with a
"Teams buzz in" checkbox. The database's clock orders the buzzes, so
the result doesn't depend on phone clocks. The control room lists the
order and clears it per question (B); the scoreboard shows who buzzed
first with a ding.

Buzzes follow the existing rules: token-gated route handlers with the
service-role client, RLS on the new table, and data-free realtime pings
on a new buzzer:{eventId} channel.

Needs supabase/migrations/0003_buzzer.sql applied before deploying.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/check-rls.mjs

@@ -2,7 +2,7 @@
 // Run with: npm run check:rls
 import { createClient } from "@supabase/supabase-js";
 
-const TABLES = ["events", "teams", "games", "criteria", "judges", "scores", "adjustments"];
+const TABLES = ["events", "teams", "games", "criteria", "judges", "scores", "adjustments", "buzzes"];
 
 const url = process.env.NEXT_PUBLIC_SUPABASE_URL;
 const anonKey = process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY;