QML's JS engine does not support ES module export/import syntax.
Replace bare export with a CommonJS guard that only runs under Node.js,
so the plugin loads in QML while tests still work.
- Extract peer parsing and exit-node command logic into lib.js
- Add ↗ button on peers that are ExitNodeOption candidates
- Highlight active exit node in primary color
- Add clear (×) button next to current exit node label
- Add unit tests for parsePeers and makeExitNodeCommand
