P2P Signaling Server (Cloudflare Workers)
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Endpoints:
  GET /create
    Returns: { "code": "UUID" } (Optional: Useful for unique room generation)

  WS  /match/{ANY_KEY}
    Role-based P2P signaling using a shared key or UUID.

Usage Flow:
  1. Both: Choose a shared {ANY_KEY} (e.g., "secret-room-123")
  2. Host: Connect to WS /match/{ANY_KEY}
     Receive: { "type": "assigned_role", "role": "host" }
  3. Guest: Connect to WS /match/{ANY_KEY}
     Receive: { "type": "assigned_role", "role": "guest" }
  4. Both: Receive { "type": "matched" } once both are connected.
  5. Both: Obtain Global IP/Port via STUN, then send:
     Send: { "type": "offer", "address": "1.2.3.4:12345" }
  6. Both: Receive { "type": "peer", "address": "1.2.3.4:12345" }
     Final Step: Initiate UDP hole punching toward the peer.