Remote comms: Add direct transport support (QUIC + TCP) for Node.js connections

[sirtimid]

Problem

Currently only WebSocket/WebRTC transports are configured in connection-factory.ts, limiting Node.js environments to relay-based connections. Direct connections would provide better performance for server-to-server communication.

Proposal

Add support for direct transports — QUIC (UDP) and TCP — for Node.js-to-Node.js communication without requiring a relay server.

QUIC (quic-v1)

Uses @chainsafe/libp2p-quic (Rust-backed native bindings, Node.js only). Advantages over TCP:

• No head-of-line blocking — natively multiplexes streams over UDP
• Faster connection setup — single RTT for encrypted, multiplexed connection
• Ossification resistance — fully encrypted headers

See: https://libp2p.io/guides/quic/

TCP

Uses @libp2p/tcp for standard TCP connections. Useful as a fallback where UDP/QUIC may be blocked.

API Design

User-facing (RemoteCommsOptions): Users declare addresses — the platform auto-detects required transports.

await kernel.initRemoteComms({
  directListenAddresses: [
    '/ip4/0.0.0.0/udp/0/quic-v1',  // QUIC
    '/ip4/0.0.0.0/tcp/0',           // TCP
  ],
});

Address discovery: kernel.getStatus() exposes listenAddresses with OS-assigned ports. Peers exchange addresses out-of-band and register them via kernel.registerLocationHints().

Acceptance Criteria

• directListenAddresses option on RemoteCommsOptions for users to declare listen addresses
• NodejsPlatformServices auto-detects QUIC (/quic-v1) and TCP (/tcp/) from address strings
• ConnectionFactory accepts multiple directTransports (array of transport + listen addresses)
• QUIC transport loaded via @chainsafe/libp2p-quic when QUIC addresses present
• TCP transport loaded via @libp2p/tcp when TCP addresses present
• Both transports can be used simultaneously
• Direct addresses tried before relay fallback in candidateAddressStrings()
• kernel.getStatus() exposes listenAddresses when remote comms connected
• kernel.registerLocationHints() available for out-of-band address exchange
• Bootstrap peer discovery conditional (omitted when no relays provided)
• Browser environments continue to work (WebSocket/WebRTC only)
• Unit tests for transport configuration, address merging, and auto-detection
• E2E tests for direct QUIC and TCP connections between Node.js instances