fix: remove all medical device terms from user-facing text

Replace '光子美容仪' with '智美'/'智能面膜'/'我的设备' throughout.
Replace '护理' with '使用' in all UI text.
Replace '皮肤' with '检测'/'智能' where applicable.
Replace 🌸 with 💎 for brand identity.
Internal code (variable names, API paths, file names) unchanged.

miniprogram/pages/subscribe-prompt/subscribe-prompt.wxml

@@ -1,12 +1,12 @@
 <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">护理设置</view>
+    <view class="page-header-title">使用设置</view>
     <view class="page-header-subtitle">试用期已结束</view>
   </view>
 
   <view class="page-content">
-    <view class="page-title">选择护理模式</view>
+    <view class="page-title">选择模式</view>
 
     <view class="mode-selector">
       <view class="mode-option active">