feat: display scan-ready enrollment QR codes for OTP tokens

tests/components/token-qr.test.tsx

@@ -0,0 +1,29 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { TokenQrDialog } from "../../src/components/otp/TokenQrDialog";
+import { parseOtpAuth } from "../../src/otp/profile";
+
+describe("token QR display", () => {
+  it("reports encoder limits without displaying an empty QR or allowing download", () => {
+    const { profile } = parseOtpAuth(
+      `otpauth://totp/${"a".repeat(500)}?secret=JBSWY3DPEHPK3PXP`,
+    );
+    render(<TokenQrDialog profile={profile} onClose={vi.fn()} />);
+    expect(screen.getByRole("alert")).toHaveTextContent(/version 10/iu);
+    expect(screen.queryByRole("img")).not.toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Download QR" })).toBeDisabled();
+  });
+
+  it("identifies nonportable time parameters without showing the plaintext seed", () => {
+    const { profile } = parseOtpAuth(
+      "otpauth://totp/Example:alice?secret=JBSWY3DPEHPK3PXP&issuer=Example&t0=100",
+    );
+    render(<TokenQrDialog profile={profile} onClose={vi.fn()} />);
+    expect(
+      screen.getByText(/Some authenticators ignore/iu),
+    ).toBeInTheDocument();
+    expect(screen.getByRole("dialog").textContent).not.toContain(
+      "JBSWY3DPEHPK3PXP",
+    );
+  });
+});