Track installer downloads by platform via license server API.

Fire-and-forget POST on Platforms download clicks with tests and configurable tracking URL.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/trackDownload.test.ts

@@ -0,0 +1,47 @@
+import assert from "node:assert/strict";
+import { afterEach, describe, it, mock } from "node:test";
+
+import {
+  DEFAULT_LICENSE_TRACKING_BASE,
+  resolveTrackDownloadUrl,
+  trackDownload,
+} from "./trackDownload";
+
+describe("trackDownload", () => {
+  afterEach(() => {
+    mock.restoreAll();
+  });
+
+  it("builds default tracking URL", () => {
+    assert.equal(
+      resolveTrackDownloadUrl(DEFAULT_LICENSE_TRACKING_BASE),
+      "https://license.ttrpgplayer.ru/v1/track/download",
+    );
+  });
+
+  it("normalizes base URL without trailing slash", () => {
+    assert.equal(
+      resolveTrackDownloadUrl("https://license.example.test"),
+      "https://license.example.test/v1/track/download",
+    );
+  });
+
+  it("POSTs platform with keepalive and swallows errors", async () => {
+    const fetchMock = mock.fn(() => Promise.reject(new Error("network down")));
+    globalThis.fetch = fetchMock;
+
+    trackDownload("macos");
+
+    await new Promise((resolve) => setTimeout(resolve, 0));
+
+    assert.equal(fetchMock.mock.calls.length, 1);
+    const call = fetchMock.mock.calls[0];
+    assert.ok(call);
+    const [url, init] = call.arguments as unknown as [string, RequestInit];
+    assert.equal(url, "https://license.ttrpgplayer.ru/v1/track/download");
+    assert.equal(init.method, "POST");
+    assert.equal(init.keepalive, true);
+    assert.deepEqual(init.headers, { "Content-Type": "application/json" });
+    assert.equal(init.body, JSON.stringify({ platform: "macos" }));
+  });
+});