Fix Linux CI build — don't block stock Electron download

On non-Windows (CI), skip writing path.txt so electron-nightly still
downloads the native Linux binary into dist/. The patched Windows
binary goes to dist-win/ and is used via -c.electronDist override.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/download-electron.js

@@ -174,8 +174,11 @@ async function main() {
 
     // Write path.txt so the electron package's lazy downloader (index.js)
     // considers the binary already installed and doesn't re-download stock.
-    const platformExe = process.platform === 'win32' ? 'electron.exe' : 'electron';
-    fs.writeFileSync(path.join(ELECTRON_DIST, '..', 'path.txt'), platformExe);
+    // On non-Windows (CI cross-compilation), skip this so electron-nightly still
+    // downloads the native Linux binary into dist/ for the Linux build target.
+    if (IS_WIN) {
+        fs.writeFileSync(path.join(ELECTRON_DIST, '..', 'path.txt'), 'electron.exe');
+    }
 
     // Write marker and verify
     if (fs.existsSync(VERSION_FILE)) {