fix(desktop): update Windows executable in place

.github/scripts/generate-portable-update.test.mjs

@@ -0,0 +1,41 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { generatePortableUpdate } from "./generate-portable-update.mjs";
+
+test("generates a signed Windows portable updater manifest", () => {
+  const manifest = generatePortableUpdate({
+    version: "v1.2.3-beta.1",
+    repository: "owner/repository",
+    assetName: "cursor-byok-1.2.3-beta.1-windows-amd64.zip",
+    signature: "signed-payload\n",
+  });
+
+  assert.equal(manifest.version, "1.2.3-beta.1");
+  assert.deepEqual(Object.keys(manifest.platforms), ["windows-x86_64"]);
+  assert.equal(manifest.platforms["windows-x86_64"].signature, "signed-payload");
+  assert.equal(
+    manifest.platforms["windows-x86_64"].url,
+    "https://github.com/owner/repository/releases/download/v1.2.3-beta.1/cursor-byok-1.2.3-beta.1-windows-amd64.zip",
+  );
+});
+
+test("rejects invalid inputs", () => {
+  assert.throws(() => generatePortableUpdate({
+    version: "latest",
+    repository: "owner/repository",
+    assetName: "update.zip",
+    signature: "signature",
+  }), /semantic version/);
+  assert.throws(() => generatePortableUpdate({
+    version: "1.2.3",
+    repository: "owner/repository",
+    assetName: "../update.zip",
+    signature: "signature",
+  }), /file name/);
+  assert.throws(() => generatePortableUpdate({
+    version: "1.2.3",
+    repository: "owner/repository",
+    assetName: "update.zip",
+    signature: " ",
+  }), /signature/);
+});