feat(i18n): 剩余15页全量接入中英(登录/注册/扫码/绑定/佩戴/扫描/治疗/订阅/帮助等)

- 3 个并行 agent 各管 5 页,互不重叠命名空间
- 全 App 18 页均 i18n.bind,22 命名空间/400 键中英对齐
- 动态文案(时长/天数/价格/区域)JS 内 i18n.t 计算;区域标签复用 common.regions

miniprogram/pages/scan/scan.wxml

@@ -1,20 +1,20 @@
 <view class="page">
   <view class="page-header page-header-pink" style="padding-top: {{statusBarHeight + 24}}px;">
-    <view class="nav-back" bindtap="onBack">‹ 返回</view>
-    <view class="page-header-title">扫码绑定</view>
-    <view class="page-header-subtitle">扫描设备底部二维码</view>
+    <view class="nav-back" bindtap="onBack">‹ {{i18n.common.back}}</view>
+    <view class="page-header-title">{{i18n.scan.title}}</view>
+    <view class="page-header-subtitle">{{i18n.scan.subtitle}}</view>
   </view>
 
   <view class="page-content">
     <view class="scan-area">
       <text class="scan-icon">📷</text>
-      <text class="scan-text">扫描设备二维码</text>
+      <text class="scan-text">{{i18n.scan.scanText}}</text>
     </view>
 
     <button class="btn-primary" bindtap="onScan" disabled="{{scanning}}">
-      {{scanning ? '扫描中...' : '扫码'}}
+      {{scanning ? i18n.scan.scanning : i18n.scan.scan}}
     </button>
-    <button class="btn-secondary" bindtap="onManualInput">手动输入设备号</button>
+    <button class="btn-secondary" bindtap="onManualInput">{{i18n.scan.manualInput}}</button>
 
     <view class="error-text" wx:if="{{error}}">{{error}}</view>
   </view>