Rewrite download-electron.js to download both Windows (v42) and
Linux (v43) patched binaries from bigjakk/Electron-Websocket-Fix,
matching KPC's multi-platform approach. On CI, binaries go to
dist-win/ and dist-linux/; locally the current platform replaces
dist/. Both platforms now use the patched Electron.
electron-nightly may not auto-download the Linux binary on CI.
Add explicit step to trigger download if missing. Pass electronDist
as CLI override per-platform (dist-win for Windows, dist for Linux)
instead of in config. Write path.txt on all platforms like KPC.
bigjakk