Fix random duel tag rooms using 2-player capacity

[scarletkc]

Summary

• interpolate the original random duel request type so tag mode rooms fall back to 4-player capacity calculations
• guard lookups in ROOM_find_or_create_random to skip rooms without random duel metadata
• default the capacity helper to the chosen duel type when rooms haven't been fully initialized yet

Testing

• npx coffee -c ygopro-server.coffee
• npx tsc --noEmit