fix: resolve critical audit issues across all modules

Server: add filter/search/pagination to admin list endpoints, enrich
user/device queries with JOINs and subqueries, prevent duplicate active
subscriptions on creation.

Admin console: fix record page TypeError on numeric record_id, correct
mode comparison (integer vs string), fix device detail field names and
command opcode, remove hardcoded login credentials, wire up dead buttons
(unbind, view logs, export), fix user/subscription field mappings.

Miniprogram: fix subscription status string/number mismatches across
index/treatment-setup/profile pages, fix device name field reference,
fix treatment-done null device_id by capturing at onLoad.

admin-console/src/pages/user-detail/index.vue

@@ -23,7 +23,7 @@
           <text class="stat-label">护理次数</text>
         </view>
         <view class="stat-item">
-          <text class="stat-value">{{ user.total_duration || '0h' }}</text>
+          <text class="stat-value">{{ user.total_duration ? Math.round(user.total_duration / 3600000) + 'h' : '0h' }}</text>
           <text class="stat-label">累计时长</text>
         </view>
         <view class="stat-item">
@@ -112,8 +112,7 @@ export default {
       uni.navigateTo({ url: '/pages/record/index?user_id=' + this.userId })
     },
     subStatusText(status) {
-      const map = { yearly: '年卡会员', monthly: '月卡会员', trial: '试用中', none: '未订阅' }
-      return map[status] || '未订阅'
+      return status === 1 ? '已订阅' : '未订阅'
     },
     subTypeText(type) {
       const map = { yearly: '年卡', monthly: '月卡', trial: '试用' }