fix(mapping): correct region↔IO mapping per on-device measurement

Measured on real hardware: IO1=right IO2=left IO3=top IO4=middle IO5=bottom
(0x01=right 0x02=left 0x04=top 0x08=middle 0x10=bottom). The earlier verbal
'left=IO1/upper=IO2...' spec was wrong; this reverts to the original Phase-1
mapping, which the measurement confirms.

- protocol.js REGION constants + getRegionName + REGION_NAMES
- CRITICAL: buildVendorCommand ioMasks was built from REGION.* constants whose
  values just flipped, scrambling IO slot order; pin to literal [0x01..0x10]
- diagnosis.js REGION_DEFS key↔mask; pd_region_map values unchanged (PD is
  keyed by orientation, which is stable) — right=PD5 left=PD1 top=PD2
  middle=PD3,6,7 bottom=PD4
- common.js region labels back to right/left/top/middle/bottom (上/中/下)
- treatment-setup / manual-treatment / treating / scan-report / ble-debug
  face-map bindings and REGION_MAP realigned
- verified: mock pipeline lands left→IO2, middle→IO4 correctly

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

@@ -27,11 +27,11 @@
 
     <!-- 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) -->
     <view class="face-map">
-      <view class="face-region forehead {{regions[1].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="1">{{i18n.common.regions.top}}</view>
-      <view class="face-region left-cheek {{regions[0].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="0">{{i18n.common.regions.left}}</view>
-      <view class="face-region right-cheek {{regions[4].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="4">{{i18n.common.regions.right}}</view>
-      <view class="face-region nose {{regions[2].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="2">{{i18n.common.regions.middle}}</view>
-      <view class="face-region chin {{regions[3].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="3">{{i18n.common.regions.bottom}}</view>
+      <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>
+      <view class="face-region right-cheek {{regions[0].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="0">{{i18n.common.regions.right}}</view>
+      <view class="face-region nose {{regions[3].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="3">{{i18n.common.regions.middle}}</view>
+      <view class="face-region chin {{regions[4].checked ? 'active' : ''}} {{selectedMode === 0 ? 'disabled' : ''}}" bindtap="onToggleRegion" data-idx="4">{{i18n.common.regions.bottom}}</view>
     </view>
 
     <button class="btn-primary" bindtap="onStart" disabled="{{submitting}}" loading="{{submitting}}">