feat(registration): add email confirmation UI

New ConfirmEmailPage for users to verify their email and set password.
Resend form on registration and error pages. Registration form no
longer asks for a password. Confirmation requires a button click. The
admin list marks unconfirmed requests and offers only delete for them.

src/components/ResendConfirmation.test.jsx

@@ -0,0 +1,37 @@
+// @vitest-environment jsdom
+import {afterEach, describe, expect, it, vi} from 'vitest';
+import {cleanup, fireEvent, render, screen} from '@testing-library/react';
+import ResendConfirmation from './ResendConfirmation.jsx';
+import {fetchRoutes, json} from '../test/fetchRoutes.js';
+
+vi.mock('react-i18next', () => ({
+    useTranslation: () => ({
+        t: (key, options) => (options?.minutes === undefined ? key : `${key}:${options.minutes}`),
+        i18n: {language: 'de'},
+    }),
+}));
+
+describe('ResendConfirmation', () => {
+    afterEach(cleanup);
+
+    it('sends the prefilled address and shows the same answer for any address', async () => {
+        const mock = fetchRoutes({'POST /api/registration/resend': json(204, null)});
+        render(<ResendConfirmation defaultEmail="a@b.de"/>);
+
+        fireEvent.click(screen.getByRole('button', {name: 'REGISTRATION.RESEND'}));
+
+        expect(await screen.findByText('REGISTRATION.RESEND_SENT')).toBeTruthy();
+        expect(JSON.parse(mock.mock.calls[0][1].body)).toEqual({email: 'a@b.de'});
+    });
+
+    it('shows the wait time when the IP is blocked', async () => {
+        fetchRoutes({
+            'POST /api/registration/resend': {...json(429, {}), headers: new Headers({'Retry-After': '900'})},
+        });
+        render(<ResendConfirmation/>);
+
+        fireEvent.click(screen.getByRole('button', {name: 'REGISTRATION.RESEND'}));
+
+        expect(await screen.findByText('REGISTRATION.ERROR_TOO_MANY_ATTEMPTS:15')).toBeTruthy();
+    });
+});