feat(web): add whatsapp QR login tool

src/web/qr-image.test.ts

@@ -0,0 +1,11 @@
+import { describe, expect, it } from "vitest";
+
+import { renderQrPngBase64 } from "./qr-image.js";
+
+describe("renderQrPngBase64", () => {
+  it("renders a PNG data payload", async () => {
+    const b64 = await renderQrPngBase64("clawdis");
+    const buf = Buffer.from(b64, "base64");
+    expect(buf.subarray(0, 8).toString("hex")).toBe("89504e470d0a1a0a");
+  });
+});