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>

config.js

@@ -24,7 +24,7 @@ module.exports = {
    * speed:     语速 -2~2(正数加快,0 为默认)。
    */
   tts: {
-    female: { voiceType: 502005, volume: 9, speed: 1 },
-    male:   { voiceType: 602005, volume: 9, speed: 1 }
+    female: { voiceType: 501004, volume: 9, speed: 1 },
+    male:   { voiceType: 502005, volume: 9, speed: 1 }
   }
 }