设置页改造：「设置」→「数据」，做成数据中心

- tabBar 文字 ⚙️ 设置 → 💾 数据
- Header 收敛成 标题 + 一行统计 + 上次备份时间
- 删除「关于」「温馨提示」整块装饰内容
- 「数据管理」拆成「备份」+「危险操作」两组
- 导出成功后写入 lastBackupAt，进页面格式化展示
- 图标背景从冷色统一为纸感暖色
- 底部加版本号 v2.1.3 小字

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pages/settings/settings.js

@@ -1,50 +1,56 @@
 // settings.js
 const storage = require('../../utils/storage')
 
+const LAST_BACKUP_KEY = 'lastBackupAt'
+
+function formatRelativeTime(ts) {
+  if (!ts) return '从未备份'
+  const diff = Date.now() - ts
+  if (diff < 60 * 1000) return '刚刚'
+  if (diff < 60 * 60 * 1000) return Math.floor(diff / 60000) + ' 分钟前'
+  if (diff < 24 * 60 * 60 * 1000) return Math.floor(diff / 3600000) + ' 小时前'
+  if (diff < 30 * 24 * 60 * 60 * 1000) return Math.floor(diff / 86400000) + ' 天前'
+  const d = new Date(ts)
+  return (d.getMonth() + 1) + '月' + d.getDate() + '日'
+}
+
 Page({
   data: {
-    dataCount: {
-      persons: 0,
-      anniversaries: 0
-    }
+    personsCount: 0,
+    anniversariesCount: 0,
+    lastBackupText: '从未备份',
+    version: 'v2.1.3'
   },
 
   onLoad() {
-    this.loadDataCount()
+    this.loadSummary()
   },
 
   onShow() {
-    this.loadDataCount()
+    this.loadSummary()
   },
 
-  /**
-   * 加载数据统计
-   */
-  loadDataCount() {
+  loadSummary() {
     const persons = storage.getPersons()
     const anniversaries = storage.getAnniversaries()
-    
+    const lastBackupAt = wx.getStorageSync(LAST_BACKUP_KEY) || 0
+
     this.setData({
-      dataCount: {
-        persons: persons.length,
-        anniversaries: anniversaries.length
-      }
+      personsCount: persons.length,
+      anniversariesCount: anniversaries.length,
+      lastBackupText: formatRelativeTime(lastBackupAt)
     })
   },
 
-  /**
-   * 导出数据
-   */
   onExportData() {
     const data = storage.exportData()
-    
-    // 转换为JSON字符串
     const jsonStr = JSON.stringify(data, null, 2)
-    
-    // 在小程序中，可以通过提示用户复制
+
     wx.setClipboardData({
       data: jsonStr,
       success: () => {
+        wx.setStorageSync(LAST_BACKUP_KEY, Date.now())
+        this.loadSummary()
         wx.showToast({
           title: '数据已复制到剪贴板',
           icon: 'success'
@@ -53,9 +59,6 @@ Page({
     })
   },
 
-  /**
-   * 导入数据
-   */
   onImportData() {
     wx.showModal({
       title: '导入数据',
@@ -64,7 +67,6 @@ Page({
       cancelText: '取消',
       success: (res) => {
         if (res.confirm) {
-          // 读取剪贴板
           wx.getClipboardData({
             success: (res) => {
               try {
@@ -87,25 +89,20 @@ Page({
     })
   },
 
-  /**
-   * 清空所有数据
-   */
   onClearData() {
     wx.showModal({
       title: '确认清空',
       content: '确定要清空所有数据吗？此操作不可恢复！',
       confirmText: '确认清空',
-      confirmColor: '#ff5722',
+      confirmColor: '#C8412F',
       success: (res) => {
         if (res.confirm) {
           const success = storage.clearAllData()
-          
           if (success) {
             wx.showToast({
               title: '已清空',
               icon: 'success'
             })
-            
             setTimeout(() => {
               wx.reLaunch({
                 url: '/pages/index/index'
@@ -117,4 +114,3 @@ Page({
     })
   }
 })
-