fix(vibrate): 修复旧用户震动失效 + 新增震动强度选项

根因:user_settings 早期无 vibrate 字段,getSettings 未兜底,
_remind 的 !s.vibrate 误判 undefined 为关闭,导致震动静默失效,
需手动操作开关才恢复。

- storage: getSettings 兜底 vibrate/voiceGuide/vibrateIntensity 默认值
- timer: !s.vibrate 改 === false,字段缺失视为开(与 voiceGuide 一致)
- timer: vibrate 按 vibrateIntensity 选 API(light/medium=vibrateShort,
  heavy=vibrateLong),fail 回调辅助排查
- settings: 新增"震动强度"三档(短促/标准/强烈),默认强烈

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pages/settings/settings.js

@@ -58,6 +58,12 @@ Page({
       { key: 'female', name: '女声' },
       { key: 'male', name: '男声' }
     ],
+    vibrateIntensity: 'heavy',
+    vibrateIntensityOptions: [
+      { key: 'light', name: '短促' },
+      { key: 'medium', name: '标准' },
+      { key: 'heavy', name: '强烈' }
+    ],
     icons: iconsMod.build(),
     nickName: '',
     avatarUrl: '',
@@ -92,6 +98,7 @@ Page({
       voiceGuide: s.voiceGuide,
       vibrate: s.vibrate,
       voiceGender: s.voiceGender || 'female',
+      vibrateIntensity: s.vibrateIntensity || 'heavy',
       currentThemeId: theme.id,
       theme,
       icons: iconsMod.build(theme),
@@ -253,6 +260,15 @@ Page({
     this.setData({ voiceGender: key })
   },
 
+  onSelectVibrateIntensity(e) {
+    const key = e.currentTarget.dataset.key
+    if (key === this.data.vibrateIntensity) return
+    const s = storage.getSettings()
+    s.vibrateIntensity = key
+    storage.saveSettings(s)
+    this.setData({ vibrateIntensity: key })
+  },
+
   onCopyWechat() {
     wx.setClipboardData({
       data: config.developer,

pages/settings/settings.wxml

@@ -140,6 +140,21 @@
       </view>
       <switch checked="{{vibrate}}" bindchange="onToggleVibrate" color="{{theme.primary}}"/>
     </view>
+    <view class="setting-row">
+      <view class="setting-left">
+        <image class="setting-icon" src="{{icons.notificationFill}}" mode="aspectFit"></image>
+        <text class="setting-label">震动强度</text>
+      </view>
+      <view class="segmented">
+        <view
+          class="segmented-item {{vibrateIntensity === item.key ? 'active' : ''}}"
+          wx:for="{{vibrateIntensityOptions}}"
+          wx:key="key"
+          data-key="{{item.key}}"
+          bindtap="onSelectVibrateIntensity"
+        >{{item.name}}</view>
+      </view>
+    </view>
   </ui-card>
 
   <!-- 数据管理 -->