Restructures frontend to a feature-based folder layout

Groups auth, setup, invitation, profile, users, cms, availability and
system code (services/hooks, components, schemas, mocks, pages) under
src/features/<name> instead of splitting by technical layer (api/,
components/, lib/schemas/, mocks/, pages/). Renames the old
connection-oriented `api` layer to `services` per feature, and splits
the monolithic api/types.ts into per-feature types.ts files (with
ProblemDetails/ApiResult merged into lib/api-client.ts as shared
infra). Layout-agnostic code (ui primitives, app shell, i18n, test
utils, lib) stays at the top level.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/features/users/mocks/handlers.ts

@@ -0,0 +1,118 @@
+import { http, HttpResponse } from 'msw';
+import type { UserListItem } from '@/features/users/services/types';
+import { API_BASE, mockUser } from '@/features/auth/mocks/fixtures';
+
+let mockUsers: UserListItem[] = [
+    {
+        ...mockUser,
+        createdAt: '2026-01-01T00:00:00.000Z',
+        invitationPending: false,
+        inviteLink: null,
+    },
+    {
+        id: '22222222-2222-2222-2222-222222222222',
+        email: 'admin@example.com',
+        name: 'Admin User',
+        role: 'Administrator',
+        isActive: true,
+        createdAt: '2026-01-15T00:00:00.000Z',
+        invitationPending: false,
+        inviteLink: null,
+    },
+    {
+        id: '33333333-3333-3333-3333-333333333333',
+        email: 'pending@example.com',
+        name: 'pending@example.com',
+        role: 'User',
+        isActive: true,
+        createdAt: '2026-06-01T00:00:00.000Z',
+        invitationPending: true,
+        inviteLink: '/invite/complete?token=pending-mock-token',
+    },
+];
+
+export const resetMockUsers = () => {
+    mockUsers = [
+        {
+            ...mockUser,
+            createdAt: '2026-01-01T00:00:00.000Z',
+            invitationPending: false,
+            inviteLink: null,
+        },
+        {
+            id: '22222222-2222-2222-2222-222222222222',
+            email: 'admin@example.com',
+            name: 'Admin User',
+            role: 'Administrator',
+            isActive: true,
+            createdAt: '2026-01-15T00:00:00.000Z',
+            invitationPending: false,
+            inviteLink: null,
+        },
+        {
+            id: '33333333-3333-3333-3333-333333333333',
+            email: 'pending@example.com',
+            name: 'pending@example.com',
+            role: 'User',
+            isActive: true,
+            createdAt: '2026-06-01T00:00:00.000Z',
+            invitationPending: true,
+            inviteLink: '/invite/complete?token=pending-mock-token',
+        },
+    ];
+};
+
+export const getMockUsers = () => mockUsers;
+
+export const userHandlers = [
+    http.get(`${API_BASE}/api/v1/Users`, () => HttpResponse.json(mockUsers)),
+
+    http.post(`${API_BASE}/api/v1/Users/invite`, async ({ request }) => {
+        const body = (await request.json()) as { email: string; role: string };
+        const token = `mock-token-${Date.now()}`;
+        const inviteLink = `/invite/complete?token=${token}`;
+
+        const newUser: UserListItem = {
+            id: crypto.randomUUID(),
+            email: body.email,
+            name: body.email,
+            role: body.role as UserListItem['role'],
+            isActive: true,
+            createdAt: new Date().toISOString(),
+            invitationPending: true,
+            inviteLink,
+        };
+        mockUsers = [...mockUsers, newUser];
+
+        return HttpResponse.json({ inviteLink });
+    }),
+
+    http.put(`${API_BASE}/api/v1/Users/:userId/role`, () => new HttpResponse(null, { status: 200 })),
+
+    http.put(`${API_BASE}/api/v1/Users/:userId/active`, () => new HttpResponse(null, { status: 200 })),
+
+    http.put(`${API_BASE}/api/v1/Users/me`, async ({ request }) => {
+        const body = (await request.json()) as { name: string; email: string };
+        const owner = mockUsers.find((u) => u.role === 'Owner') ?? mockUsers[0];
+        const updated: UserListItem = {
+            ...owner,
+            name: body.name,
+            email: body.email,
+        };
+        mockUsers = mockUsers.map((u) => (u.id === owner.id ? updated : u));
+        return HttpResponse.json(updated);
+    }),
+
+    http.delete(`${API_BASE}/api/v1/Users/:userId`, ({ params }) => {
+        const { userId } = params as { userId: string };
+        const ownerUser = mockUsers.find((u) => u.role === 'Owner');
+        if (userId === ownerUser?.id) {
+            return HttpResponse.json(
+                { title: 'Bad Request', detail: 'At least one Owner must remain.', status: 400 },
+                { status: 400 },
+            );
+        }
+        mockUsers = mockUsers.filter((u) => u.id !== userId);
+        return new HttpResponse(null, { status: 204 });
+    }),
+];