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/treatment-setup/treatment-setup.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">选择模式和区域</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 {{selectedMode === 0 ? 'active' : ''}}" bindtap="onSelectMode" data-value="0">
@@ -22,8 +22,8 @@
       </view>
     </view>
 
-    <view class="page-title" style="font-size:28rpx;">选择护理区域</view>
-    <view class="mode-tip" wx:if="{{selectedMode === 0}}">普通模式固定 10 分钟，护理区域默认全脸，不可调整</view>
+    <view class="page-title" style="font-size:28rpx;">选择区域</view>
+    <view class="mode-tip" wx:if="{{selectedMode === 0}}">普通模式固定 10 分钟，使用区域默认全脸，不可调整</view>
 
     <view class="face-map">
       <view class="face-region forehead {{regions[2].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="2">额头</view>
@@ -34,7 +34,7 @@
     </view>
 
     <button class="btn-primary" bindtap="onStart" disabled="{{submitting}}" loading="{{submitting}}">
-      开始护理
+      开始使用
     </button>
 
     <view class="error-text" wx:if="{{error}}">{{error}}</view>