Add Windows x64 and x86 installers and refresh release screenshots

scripts/build-windows.mjs

@@ -0,0 +1,18 @@
+import { build, Platform, Arch } from 'electron-builder';
+
+const requested = process.argv[2];
+if (requested && !['portable', 'nsis'].includes(requested)) throw new Error('Expected portable or nsis.');
+const targets = requested ? [requested] : ['portable', 'nsis'];
+// Electron 43 is the last series with Windows ia32 binaries.
+for (const [label, arch, electronVersion] of [['x64', Arch.x64, '44.3.0'], ['x86', Arch.ia32, '43.8.3']]) {
+  await build({
+    targets: Platform.WINDOWS.createTarget(targets, arch),
+    publish: 'never',
+    config: {
+      electronVersion,
+      directories: { output: `release/${label}` },
+      portable: { artifactName: `Untrace-Desktop-\${version}-portable-${label}.exe` },
+      nsis: { artifactName: `Untrace-Desktop-\${version}-setup-${label}.exe` },
+    },
+  });
+}