feat(observability): add structured application logging

Emit correlated JSON logs from the API and FunASR services, propagate request IDs to the client, and configure bounded opt-in Docker logging.

Document the host-wide Grafana/Loki query workflow and keep observability deployment ownership outside the application repository.

pages/students/index.ts

@@ -1,7 +1,9 @@
 import {
+  copyApiRequestId,
   createProfile,
   deleteProfile as deleteProfileRequest,
   getApiErrorMessage,
+  getApiRequestId,
   getProfileDefaults,
   listFeedbackRecords,
   listProfiles
@@ -107,7 +109,8 @@ Page({
     loading: false,
     saving: false,
     deletingId: '',
-    errorMessage: ''
+    errorMessage: '',
+    errorRequestId: ''
   },
 
   onShow() {
@@ -119,7 +122,7 @@ Page({
   },
 
   async refreshProfiles(showSuccess = false) {
-    this.setData({ loading: true, errorMessage: '' })
+    this.setData({ loading: true, errorMessage: '', errorRequestId: '' })
     try {
       const profiles = (await listProfiles()).map(withAcademicTermLabel)
       const filteredProfiles = filterProfiles(
@@ -139,7 +142,7 @@ Page({
       })
       if (showSuccess) wx.showToast({ title: '档案已刷新', icon: 'success' })
     } catch (error) {
-      this.setData({ errorMessage: getApiErrorMessage(error) })
+      this.setData({ errorMessage: getApiErrorMessage(error), errorRequestId: getApiRequestId(error) })
     } finally {
       this.setData({ loading: false })
     }
@@ -153,6 +156,10 @@ Page({
     void this.refreshProfiles()
   },
 
+  copyRequestId() {
+    copyApiRequestId(this.data.errorRequestId)
+  },
+
   onSearch(event: InputEvent) {
     const query = event.detail.value
     this.setData({

pages/students/index.wxml

@@ -6,7 +6,13 @@
   <text class="page-subtitle">管理学生默认信息，用于快速生成课堂反馈</text>
 
   <view wx:if="{{errorMessage}}" class="status-banner">
-    <text>{{errorMessage}}</text>
+    <view class="status-copy">
+      <text>{{errorMessage}}</text>
+      <view wx:if="{{errorRequestId}}" class="status-request-id">
+        <text>请求编号：{{errorRequestId}}</text>
+        <text class="status-action" bindtap="copyRequestId">复制</text>
+      </view>
+    </view>
     <text class="status-action" bindtap="retryLoad">重试</text>
   </view>