feat: add E2E tests for device creation and account management

10 E2E tests using NiceGUI's User fixture:
- Device creation flow and name validation
- Password change (success, wrong current, mismatch, too short)
- API token creation, TOTP registration, invalid code rejection
- Account deletion with email confirmation

Tests live in tests/e2e/ with a separate conftest that loads the
NiceGUI testing plugin. CI runs unit and E2E tests as separate steps.

tests/e2e/test_devices.py

@@ -0,0 +1,54 @@
+"""End-to-end tests for device management UI using NiceGUI's User fixture."""
+
+from unittest.mock import patch
+
+import pytest
+from nicegui.testing import User
+
+from wiregui.models.user import User as UserModel
+from tests.e2e.conftest import TEST_EMAIL, TEST_PASSWORD
+
+# Fake WG keys for testing (valid base64, 32 bytes)
+FAKE_PRIVATE_KEY = "YFake0PrivateKey00000000000000000000000000w="
+FAKE_PUBLIC_KEY = "ZFake0PublicKey000000000000000000000000000w="
+
+
+async def _login(user: User):
+    """Helper to log in via the UI."""
+    await user.open("/login")
+    user.find("Email").type(TEST_EMAIL)
+    user.find("Password").type(TEST_PASSWORD)
+    user.find("Sign in").click()
+    await user.should_see("My Devices")
+
+
+@pytest.mark.parametrize("user", [{"storage": {}}], indirect=True)
+async def test_add_device_via_ui(user: User, test_user: UserModel):
+    """Test the full flow: login → devices → add device → see it in table."""
+    with patch("wiregui.pages.devices.generate_keypair", return_value=(FAKE_PRIVATE_KEY, FAKE_PUBLIC_KEY)), \
+         patch("wiregui.pages.devices.generate_preshared_key", return_value="cHJlc2hhcmVkMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDA="):
+
+        await _login(user)
+
+        # Open create dialog
+        user.find("Add Device").click()
+        await user.should_see("New Device")
+
+        # Fill device name and submit
+        user.find("Device Name").type("Test Laptop")
+        user.find("Create").click()
+
+        # Should see config dialog with the device config
+        await user.should_see("Test Laptop")
+
+
+@pytest.mark.parametrize("user", [{"storage": {}}], indirect=True)
+async def test_add_device_requires_name(user: User, test_user: UserModel):
+    """Test that creating a device without a name shows an error."""
+    await _login(user)
+
+    # Open create dialog and submit without name
+    user.find("Add Device").click()
+    await user.should_see("New Device")
+    user.find("Create").click()
+    await user.should_see("Device name is required")