Show a login notice when a session ends due to idle timeout.

Return a distinct session_idle error from the API and reload to /login with a clear signed-out message.

webui/src/api/client.test.ts

@@ -14,6 +14,7 @@ import {
   fetchStatus,
   fetchUsers,
   getApiBaseUrl,
+  login,
   patchAction,
   saveNetwork,
   saveSecurity,
@@ -716,3 +717,71 @@ describe('actions API', () => {
     )
   })
 })
+
+describe('session idle redirect', () => {
+  afterEach(() => {
+    vi.restoreAllMocks()
+  })
+
+  it('reloads to login when an authenticated call returns session_idle', async () => {
+    const assign = vi.fn()
+    vi.stubGlobal('location', {
+      pathname: '/configuration/security',
+      assign,
+    })
+
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 401,
+      clone: () => ({
+        json: async () => ({ error: 'session_idle' }),
+      }),
+      json: async () => ({ error: 'session_idle' }),
+    })
+
+    await expect(fetchStatus(fetchMock)).rejects.toThrow()
+    expect(assign).toHaveBeenCalledWith('/login?reason=idle')
+  })
+
+  it('does not redirect on login 401', async () => {
+    const assign = vi.fn()
+    vi.stubGlobal('location', {
+      pathname: '/login',
+      assign,
+    })
+
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 401,
+      clone: () => ({
+        json: async () => ({ error: 'invalid credentials' }),
+      }),
+      json: async () => ({ error: 'invalid credentials' }),
+    })
+
+    await expect(login('Admin', 'wrong', '', fetchMock)).rejects.toThrow(
+      'invalid credentials',
+    )
+    expect(assign).not.toHaveBeenCalled()
+  })
+
+  it('does not redirect for generic authentication required', async () => {
+    const assign = vi.fn()
+    vi.stubGlobal('location', {
+      pathname: '/',
+      assign,
+    })
+
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 401,
+      clone: () => ({
+        json: async () => ({ error: 'authentication required' }),
+      }),
+      json: async () => ({ error: 'authentication required' }),
+    })
+
+    await expect(fetchStatus(fetchMock)).rejects.toThrow()
+    expect(assign).not.toHaveBeenCalled()
+  })
+})