feat: remove Account page and add PassthroughLanding page

- Deleted the Account page and its associated logic.
- Introduced a new PassthroughLanding page for users without management access.
- Updated Settings page to conditionally display the Users link for admin users.
- Enhanced UsersPage to support passthrough user role, including invite functionality and user detail modal.
- Updated tests to reflect changes in user roles and navigation.

frontend/src/pages/__tests__/Settings.test.tsx

@@ -10,7 +10,7 @@ const translations: Record<string, string> = {
   'settings.system': 'System',
   'navigation.notifications': 'Notifications',
   'settings.smtp': 'Email (SMTP)',
-  'settings.account': 'Account',
+  'navigation.users': 'Users',
 }
 
 const t = (key: string) => translations[key] ?? key
@@ -19,6 +19,10 @@ vi.mock('react-i18next', () => ({
   useTranslation: () => ({ t }),
 }))
 
+vi.mock('../../hooks/useAuth', () => ({
+  useAuth: () => ({ user: { user_id: 1, role: 'admin', name: 'Admin' } }),
+}))
+
 const renderWithRoute = (route: string) =>
   render(
     <MemoryRouter initialEntries={[route]}>
@@ -27,7 +31,7 @@ const renderWithRoute = (route: string) =>
           <Route path="system" element={<div>System Page</div>} />
           <Route path="notifications" element={<div>Notifications Page</div>} />
           <Route path="smtp" element={<div>SMTP Page</div>} />
-          <Route path="account" element={<div>Account Page</div>} />
+          <Route path="users" element={<div>Users Page</div>} />
         </Route>
       </Routes>
     </MemoryRouter>
@@ -46,12 +50,12 @@ describe('Settings page', () => {
     expect(screen.getByText('System Page')).toBeInTheDocument()
   })
 
-  it('keeps navigation order consistent', () => {
+  it('keeps navigation order consistent for admin', () => {
     renderWithRoute('/settings/notifications')
 
     const links = screen.getAllByRole('link')
     const labels = links.map(link => link.textContent)
 
-    expect(labels).toEqual(['System', 'Notifications', 'Email (SMTP)', 'Account'])
+    expect(labels).toEqual(['System', 'Notifications', 'Email (SMTP)', 'Users'])
   })
 })

frontend/src/pages/__tests__/UsersPage.test.tsx

@@ -22,6 +22,20 @@ vi.mock('../../api/users', () => ({
   acceptInvite: vi.fn(),
   previewInviteURL: vi.fn(),
   resendInvite: vi.fn(),
+  getProfile: vi.fn(),
+  updateProfile: vi.fn(),
+  regenerateApiKey: vi.fn(),
+}))
+
+vi.mock('../../hooks/useAuth', () => ({
+  useAuth: vi.fn().mockReturnValue({
+    user: { user_id: 1, role: 'admin', name: 'Admin User', email: 'admin@example.com' },
+    changePassword: vi.fn().mockResolvedValue(undefined),
+    isAuthenticated: true,
+    isLoading: false,
+    login: vi.fn(),
+    logout: vi.fn(),
+  }),
 }))
 
 vi.mock('../../api/proxyHosts', () => ({
@@ -78,6 +92,18 @@ const mockUsers = [
     created_at: '2024-01-01T00:00:00Z',
     updated_at: '2024-01-01T00:00:00Z',
   },
+  {
+    id: 4,
+    uuid: '999-000',
+    email: 'passthrough@example.com',
+    name: 'Passthrough User',
+    role: 'passthrough' as const,
+    enabled: true,
+    invite_status: 'accepted' as const,
+    permission_mode: 'allow_all' as const,
+    created_at: '2024-01-01T00:00:00Z',
+    updated_at: '2024-01-01T00:00:00Z',
+  },
 ]
 
 const mockProxyHosts = [
@@ -127,8 +153,8 @@ describe('UsersPage', () => {
       expect(screen.getByText('User Management')).toBeTruthy()
     })
 
-    expect(screen.getByText('Admin User')).toBeTruthy()
-    expect(screen.getByText('admin@example.com')).toBeTruthy()
+    expect(screen.getAllByText('Admin User').length).toBeGreaterThan(0)
+    expect(screen.getAllByText('admin@example.com').length).toBeGreaterThan(0)
     expect(screen.getByText('Regular User')).toBeTruthy()
     expect(screen.getByText('user@example.com')).toBeTruthy()
   })
@@ -346,6 +372,58 @@ describe('UsersPage', () => {
     })
   })
 
+  it('renders passthrough role badge', async () => {
+    vi.mocked(usersApi.listUsers).mockResolvedValue(mockUsers)
+
+    renderWithQueryClient(<UsersPage />)
+
+    await waitFor(() => {
+      expect(screen.getByText('Passthrough')).toBeTruthy()
+    })
+  })
+
+  it('renders My Profile card for current user', async () => {
+    vi.mocked(usersApi.listUsers).mockResolvedValue(mockUsers)
+
+    renderWithQueryClient(<UsersPage />)
+
+    await waitFor(() => {
+      expect(screen.getByText('My Profile')).toBeTruthy()
+    })
+  })
+
+  it('shows passthrough option in invite role select', async () => {
+    vi.mocked(usersApi.listUsers).mockResolvedValue(mockUsers)
+
+    renderWithQueryClient(<UsersPage />)
+
+    const user = userEvent.setup()
+    await waitFor(() => expect(screen.getByText('Invite User')).toBeTruthy())
+    await user.click(screen.getByRole('button', { name: /Invite User/i }))
+
+    await waitFor(() => {
+      const roleSelect = screen.getByLabelText('Role') as HTMLSelectElement
+      const options = Array.from(roleSelect.options).map(o => o.value)
+      expect(options).toContain('passthrough')
+    })
+  })
+
+  it('opens detail modal when edit button is clicked', async () => {
+    vi.mocked(usersApi.listUsers).mockResolvedValue(mockUsers)
+
+    renderWithQueryClient(<UsersPage />)
+
+    await waitFor(() => expect(screen.getByText('Regular User')).toBeTruthy())
+
+    const user = userEvent.setup()
+    const editButtons = screen.getAllByTitle('Edit User')
+    await user.click(editButtons[1])
+
+    await waitFor(() => {
+      expect(screen.getByRole('dialog', { name: /Edit User/i })).toBeTruthy()
+    })
+  })
+
   describe('URL Preview in InviteModal', () => {
     afterEach(() => {
       vi.useRealTimers()