fix: improve UX and fix admin console display issues

Miniprogram:
- Add back buttons to all custom-nav pages
- Add debug/mock buttons (BLE connect, wear check, treatment)
  controlled by __DEV__ flag (hidden in prod)

Admin console:
- Fix log page using nonexistent fields (operator_type, target_type)
  now correctly reads admin_id/user_id/action/detail from API
- Fix subscription date fields (started_at→start_time, expired_at→expire_time)
- Wire up subscription detail/extend/renew action buttons
- Wire up device detail "查看完整日志" button
- Add "创建订阅" button to subscription toolbar
- Fix subscription status mapping (2=expired, 3=cancelled)

Docs:
- Add detailed architecture docs for server, miniprogram, admin console

admin-console/src/pages/subscription/index.vue

@@ -2,6 +2,7 @@
   <AdminLayout currentPage="/pages/subscription/index">
     <view class="toolbar">
       <view class="header-actions">
+        <button class="btn-primary btn-sm" @click="showCreate = true">创建订阅</button>
         <button class="btn-default btn-sm" @click="onExport">导出报表</button>
       </view>
     </view>
@@ -53,16 +54,15 @@
             <text class="t-td flex2">{{ item.nickname || item.user_id }}</text>
             <text class="t-td flex1">{{ planText(item.plan) }}</text>
             <text class="t-td flex1">¥{{ item.amount || '-' }}</text>
-            <text class="t-td flex2">{{ formatDate(item.started_at) }}</text>
-            <text class="t-td flex2">{{ formatDate(item.expired_at) }}</text>
+            <text class="t-td flex2">{{ formatDate(item.start_time) }}</text>
+            <text class="t-td flex2">{{ formatDate(item.expire_time) }}</text>
             <text class="t-td flex1">
               <text :class="statusBadge(item.status)">{{ statusText(item.status) }}</text>
             </text>
             <text class="t-td flex1">
-              <text class="action-link">详情</text>
-              <text class="action-link" v-if="item.status === 1">延期</text>
-              <text class="action-link" v-if="item.status === 2">开通</text>
-              <text class="action-link" v-if="item.status === 3">续费</text>
+              <text class="action-link" @click="onDetail(item)">详情</text>
+              <text class="action-link" v-if="item.status === 1" @click="onExtend(item)">延期</text>
+              <text class="action-link" v-if="item.status === 2 || item.status === 3" @click="onRenew(item)">续费</text>
             </text>
           </view>
         </view>
@@ -166,16 +166,49 @@ export default {
         this.creating = false
       }
     },
+    onDetail(item) {
+      if (item.user_id) {
+        uni.navigateTo({ url: '/pages/user-detail/index?user_id=' + item.user_id })
+      }
+    },
+    onExtend(item) {
+      var self = this
+      uni.showModal({
+        title: '延期订阅',
+        content: '为用户 #' + item.user_id + ' 延期 30 天？',
+        success: async function (res) {
+          if (res.confirm) {
+            try {
+              await post('/api/v1/admin/subscriptions', {
+                user_id: String(item.user_id),
+                plan: item.plan || 'monthly',
+                days: 30
+              })
+              uni.showToast({ title: '延期成功', icon: 'success' })
+              self.loadSubscriptions()
+            } catch (e) {
+              uni.showToast({ title: '操作失败', icon: 'none' })
+            }
+          }
+        }
+      })
+    },
+    onRenew(item) {
+      this.createForm.user_id = String(item.user_id || '')
+      this.createForm.plan = item.plan || 'monthly'
+      this.createForm.days = 30
+      this.showCreate = true
+    },
     planText(plan) {
       const map = { monthly: '月卡', quarterly: '季卡', yearly: '年卡', trial: '试用' }
       return map[plan] || plan || '-'
     },
     statusText(status) {
-      const map = { 1: '生效中', 2: '试用中', 3: '已过期' }
+      const map = { 1: '生效中', 2: '已过期', 3: '已取消' }
       return map[status] || '-'
     },
     statusBadge(status) {
-      const map = { 1: 'badge badge-success', 2: 'badge badge-warning', 3: 'badge badge-error' }
+      const map = { 1: 'badge badge-success', 2: 'badge badge-error', 3: 'badge badge-default' }
       return map[status] || 'badge badge-default'
     },
     formatDate: formatDateShort,
@@ -188,7 +221,7 @@ export default {
         exportCSV('subscriptions_' + new Date().toISOString().slice(0, 10) + '.csv',
           ['用户', '订阅类型', '订单金额', '开始日期', '到期日期', '状态'],
           records.map(function (r) {
-            return [r.nickname || r.user_id || '', planMap[r.plan] || r.plan || '', r.amount || '', r.started_at ? r.started_at.slice(0, 10) : '', r.expired_at ? r.expired_at.slice(0, 10) : '', statusMap[r.status] || '']
+            return [r.nickname || r.user_id || '', planMap[r.plan] || r.plan || '', r.amount || '', r.start_time ? String(r.start_time).slice(0, 10) : '', r.expire_time ? String(r.expire_time).slice(0, 10) : '', statusMap[r.status] || '']
           })
         )
         uni.showToast({ title: '导出成功', icon: 'success' })