style(web): 通知中心列表行布局重构与时间标签格式化

- TopBar 通知行改为 row-main/row-head/row-foot 结构化布局，标题加粗、分类改为 pill、箭头随标题右侧
- formatNotificationTime 改名 formatNotificationTimeLabel，新增 ISO/短日期直通匹配与超长截断兜底
- 更新 sidebar-document-unread-dot 测试

web/tests/sidebar-document-unread-dot.test.mjs

@@ -96,6 +96,25 @@ test('topbar bell owns document center unread notifications', () => {
   assert.doesNotMatch(topbarStyles, /\.notification-dot/)
 })
 
+test('topbar notification popover uses inbox-style rows with formatted time labels', () => {
+  assert.match(topbar, /class="notification-row-main"/)
+  assert.match(topbar, /class="notification-row-head"/)
+  assert.match(topbar, /class="notification-row-title"/)
+  assert.match(topbar, /class="notification-context"/)
+  assert.match(topbar, /class="notification-row-foot"/)
+  assert.match(topbar, /class="notification-category-pill"/)
+  assert.match(topbar, /class="notification-time"/)
+  assert.match(topbar, /class="notification-row-action"/)
+  assert.match(topbar, /timeLabel:\s*formatNotificationTimeLabel\(row\.updatedAt \|\| row\.createdAt\)/)
+  assert.match(topbar, /timeLabel:\s*formatNotificationTimeLabel\(item\.time \|\| item\.updatedAt \|\| item\.due\)/)
+  assert.doesNotMatch(topbar, /<time>\{\{ item\.time \}\}<\/time>/)
+  assert.match(topbarStyles, /\.notification-row\s*\{[\s\S]*grid-template-columns:\s*36px minmax\(0,\s*1fr\);/)
+  assert.match(topbarStyles, /\.notification-context\s*\{[\s\S]*-webkit-line-clamp:\s*2;/)
+  assert.match(topbarStyles, /\.notification-row-foot\s*\{[\s\S]*justify-content:\s*space-between;/)
+  assert.match(topbarStyles, /\.notification-time\s*\{[\s\S]*font-variant-numeric:\s*tabular-nums;/)
+  assert.match(topbarStyles, /\.notification-row-action\s*\{[\s\S]*width:\s*28px;[\s\S]*height:\s*28px;/)
+})
+
 test('topbar notification state is persisted through backend API with local fallback', () => {
   assert.match(notificationStatesService, /apiRequest\('\/notification-states'\)/)
   assert.match(notificationStatesService, /apiRequest\('\/notification-states',\s*\{[\s\S]*method:\s*'POST'/)