v1.0.1 — PeerConnection failed handling, CLI arguments, and docs

[1ureka]

This release addresses a WebRTC lifecycle discrepancy, adds non-interactive
launch support, and improves documentation.

Changes

• fix: Automatically close the DataChannel (and all sockets) when the
  PeerConnection enters the failed state. pion/webrtc does not propagate this
  state change to DataChannels the way browsers do, so an explicit teardown is
  now triggered to match the expected lifecycle.

• feat: Add command-line flags (-role, -port, -wsPort, -wsUrl,
  -wsListen) for fully non-interactive launches. This is especially useful for
  LAN deployments where VS Code Port Forwarding is unnecessary — the Host can
  use -wsListen to bind the signaling server to all interfaces, and the Client
  connects directly via the Host's LAN IP.

• docs: Fix the Go Report Card badge link (now points to the report page)
  and add a new "CLI Arguments" section to the README with flag descriptions,
  examples, and a tip on LAN usage.