feat: production readiness — feature gaps + config hardening

Miniprogram:
- Add BLE reconnect button on home page when disconnected
- Add loading states to index, profile, subscribe-plans pages
- Add profile editing (avatar + nickname) with COS upload
- Enable pull-to-refresh on history page
- Fix auto-scan self.options → self.data inconsistency
- Add console.error to silent catch blocks
- Gate 'Simple Peripheral' BLE scan behind __DEV__ flag
- Add production config comment to env.js

Admin console:
- Add empty state '暂无数据' to all 5 list views
- Replace plain text plan input with select dropdown
- Add type="date" to record date filters
- Add production config comment

Server:
- CORS origin restricted in production (env CORS_ORIGIN)
- DB pool size configurable via DB_POOL_SIZE env var
- .env.example updated with WeChat Pay + production fields

miniprogram/pages/profile/profile.wxml

@@ -1,11 +1,18 @@
 <view class="page">
-  <view class="page-content">
+  <view class="loading-container" wx:if="{{loading}}">
+    <view class="loading-spinner"></view>
+    <text class="loading-text">加载中...</text>
+  </view>
+
+  <view class="page-content" wx:if="{{!loading}}">
     <view class="user-row">
-      <view class="user-avatar">👤</view>
+      <image class="user-avatar-img" wx:if="{{userInfo.avatar}}" src="{{userInfo.avatar}}" mode="aspectFill"></image>
+      <view class="user-avatar" wx:else>👤</view>
       <view class="user-info">
         <view class="user-name">{{userInfo.nickname || '未登录'}}</view>
         <view class="user-phone">{{userInfo.phone || ''}}</view>
       </view>
+      <view class="edit-profile-btn" bindtap="onEditProfile">编辑资料</view>
     </view>
 
     <view class="sub-card" wx:if="{{subscription && subscription.status === 'active' && subRemaining > 0}}">
@@ -55,4 +62,23 @@
 
     <view class="logout-btn" bindtap="onLogout">退出登录</view>
   </view>
+
+  <!-- Edit profile modal -->
+  <view class="edit-mask" wx:if="{{editing}}" bindtap="onCancelEdit"></view>
+  <view class="edit-modal" wx:if="{{editing}}">
+    <view class="edit-modal-title">编辑资料</view>
+    <view class="edit-avatar-row" bindtap="onPickAvatar">
+      <image class="edit-avatar-img" wx:if="{{editAvatarUrl}}" src="{{editAvatarUrl}}" mode="aspectFill"></image>
+      <view class="edit-avatar-placeholder" wx:else>👤</view>
+      <text class="edit-avatar-hint">点击更换头像</text>
+    </view>
+    <view class="edit-field">
+      <text class="edit-label">昵称</text>
+      <input class="edit-input" value="{{editNickname}}" bindinput="onEditNicknameInput" placeholder="请输入昵称" maxlength="20" />
+    </view>
+    <view class="edit-actions">
+      <button class="btn-secondary edit-btn" bindtap="onCancelEdit">取消</button>
+      <button class="btn-primary edit-btn" bindtap="onSaveProfile" disabled="{{saving}}" loading="{{saving}}">保存</button>
+    </view>
+  </view>
 </view>