docs: fix stale region-layout comments to match measured mapping

miniprogram/pages/treatment-setup/treatment-setup.wxml

@@ -25,7 +25,7 @@
     <view class="page-title" style="font-size:28rpx;">{{i18n.setup.selectRegion}}</view>
     <view class="mode-tip" wx:if="{{selectedMode === 0}}">{{i18n.setup.normalTip}}</view>
 
-    <!-- 位置↔idx 对应新纵列布局：idx0=左(0x01) idx1=中上(0x02) idx2=中(0x04) idx3=中下(0x08) idx4=右(0x10) -->
+    <!-- 位置↔idx（实测 IO↔物理位置）：idx0=右(0x01) idx1=左(0x02) idx2=上(0x04) idx3=中(0x08) idx4=下(0x10) -->
     <view class="face-map">
       <view class="face-region forehead {{regions[2].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="2">{{i18n.common.regions.top}}</view>
       <view class="face-region left-cheek {{regions[1].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="1">{{i18n.common.regions.left}}</view>