When T3 Code web mode is accessed via HTTPS (e.g. through a reverse proxy
or Tailscale Serve), the WebSocket connection must use wss:// instead of
ws://. Browsers block mixed content — an insecure ws:// connection
initiated from an HTTPS page.

Fix: derive the WebSocket protocol from window.location.protocol.

Co-authored-by: PatrickBauer <patrick@patrickbauer.dev>