feat: apply standard login page design

frontend/e2e/mobile-ui.spec.ts

@@ -213,10 +213,37 @@ test('settings match the approved paper-ledger geometry and action hierarchy', a
   expect(logoutBox!.width).toBeGreaterThanOrEqual(88)
   expect(logoutBox!.height).toBeGreaterThanOrEqual(isMobileContract ? 44 : 40)
   allowExpectedError(page, 'requestfailed: POST http://127.0.0.1:5173/api/v1/auth/logout net::ERR_ABORTED')
+  await page.route('**/api/v1/auth/logout', route => route.fulfill({ status: 204 }))
   await logout.click()
   await expect(page.getByRole('button', { name: '登录', exact: true })).toBeVisible()
-  await expect(page.getByText('欢迎回来，继续把生活理顺。')).toBeVisible()
-  expect(await page.request.get('/api/v1/me')).not.toBeOK()
+  await expect(page.getByRole('heading', { name: '欢迎回来', exact: true })).toBeVisible()
+  await expect(page.getByText('登录后继续处理今天的事项。')).toBeVisible()
+  await expect(page.getByText('登录后继续你的清单')).toBeVisible()
+  const authGeometry = await page.locator('.auth-card').evaluate(element => {
+    const card = element as HTMLElement
+    const cardRect = card.getBoundingClientRect()
+    const inputRects = [...card.querySelectorAll<HTMLElement>('input')].map(input => input.getBoundingClientRect())
+    const buttonRect = card.querySelector<HTMLElement>('button.primary')!.getBoundingClientRect()
+    return {
+      viewportWidth: innerWidth,
+      documentOverflow: document.documentElement.scrollWidth - document.documentElement.clientWidth,
+      card: { left: cardRect.left, right: cardRect.right, width: cardRect.width },
+      brand: {
+        fontSize: getComputedStyle(card.querySelector<HTMLElement>('.auth-brand .brand')!).fontSize,
+        logoWidth: card.querySelector<HTMLElement>('.auth-brand .brand-logo')!.getBoundingClientRect().width,
+      },
+      inputHeights: inputRects.map(rect => rect.height),
+      buttonHeight: buttonRect.height,
+    }
+  })
+  expect(authGeometry.documentOverflow).toBe(0)
+  const expectedCardWidth = Math.min(400, authGeometry.viewportWidth - (isMobileContract ? 36 : 48))
+  expect(authGeometry.card.width).toBeCloseTo(expectedCardWidth, 0)
+  expect(authGeometry.card.left).toBeCloseTo((authGeometry.viewportWidth - expectedCardWidth) / 2, 0)
+  expect(authGeometry.card.right).toBeCloseTo((authGeometry.viewportWidth + expectedCardWidth) / 2, 0)
+  expect(authGeometry.brand).toEqual({ fontSize: '28px', logoWidth: 34 })
+  expect(authGeometry.inputHeights.every(height => height >= 46)).toBeTruthy()
+  expect(authGeometry.buttonHeight).toBeGreaterThanOrEqual(46)
 })
 
 test('task, habit, countdown, memo, action and confirmation overlays share the modal contract', async ({ page }, testInfo) => {