Remote comms: Add TCP transport support 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 TCP connections would provide better performance for server-to-server communication.

Expected Behavior

Enable direct TCP connections for remote comms between Node.js instances to bypass relay requirements.

Implementation

Files to Modify

File	Changes
platform/connection-factory.ts	Add TCP transport conditionally for Node.js

Approach

1. Detect runtime environment

   • Check if running in Node.js vs browser
   • Use environment detection (e.g., typeof process \!== 'undefined')

2. Add TCP transport for Node.js (in ConnectionFactory.#init())

   import { tcp } from '@libp2p/tcp';
   
   // In transports array:
   ...(isNodeJS ? [tcp()] : []),

3. Add TCP listening addresses for Node.js

   addresses: {
     listen: [
       '/webrtc',
       '/p2p-circuit',
       ...(isNodeJS ? ['/ip4/0.0.0.0/tcp/0'] : []),
     ],
   }

4. Update candidateAddressStrings()

   • Try direct TCP addresses before relay paths when available
   • Prioritize direct connections over relayed ones

Dependencies

• @libp2p/tcp package

Acceptance Criteria

• TCP transport loaded when running in Node.js
• TCP listening address configured in Node.js mode
• Direct TCP connections attempted before relay fallback
• Browser environments continue to work (WebSocket/WebRTC only)
• Unit tests verify transport configuration per environment
• E2E test for direct TCP connection between Node.js instances