feat(voice): 语音参数移入 config.js + 设置页男女声切换

- config: 新增 tts.female/male 两组参数(voiceType/volume/speed),
  直接改数字即可调音色,无需改逻辑代码
- storage: getSettings 兜底 voiceGender(旧用户迁移为女声)
- voice: 新增 _getTtsParams 读 config+性别;缓存 key 含完整参数,
  改音色/音量/性别自动重新合成,无需手动清缓存
- settings: 训练偏好加"语音音色"segmented(女声/男声)
- tts 云函数: _synthesize 用传入 opts 合成;_upload 路径含 voiceType
  (男/女不同文件);需重新部署

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

pages/settings/settings.js

@@ -53,6 +53,11 @@ Page({
     currentPlanId: 'beginner',
     voiceGuide: true,
     vibrate: true,
+    voiceGender: 'female',
+    voiceGenderOptions: [
+      { key: 'female', name: '女声' },
+      { key: 'male', name: '男声' }
+    ],
     icons: iconsMod.build(),
     nickName: '',
     avatarUrl: '',
@@ -86,6 +91,7 @@ Page({
       currentPlanId: s.planId,
       voiceGuide: s.voiceGuide,
       vibrate: s.vibrate,
+      voiceGender: s.voiceGender || 'female',
       currentThemeId: theme.id,
       theme,
       icons: iconsMod.build(theme),
@@ -238,6 +244,15 @@ Page({
     this.setData({ vibrate: e.detail.value })
   },
 
+  onSelectVoiceGender(e) {
+    const key = e.currentTarget.dataset.key
+    if (key === this.data.voiceGender) return
+    const s = storage.getSettings()
+    s.voiceGender = key
+    storage.saveSettings(s)
+    this.setData({ voiceGender: key })
+  },
+
   onCopyWechat() {
     wx.setClipboardData({
       data: config.developer,