feat(admin): enrich admin panel fields; add user index constraint and customer service

- admin controller: add updatedAt to interview/resume selects; add orderCount,
  todayOrders, totalRevenue to overview
- admin.vue: enrich all tabs with more fields
  - overview: order cards (count, revenue)
  - users: wxOpenid, email, createdAt, interviewCount, vipExpireAt, role badge
  - interviews: user email, updatedAt, summary preview
  - orders: title, type, channel, paidAt, wxTransactionId, refund info
  - resumes: user email, updatedAt
  - share: sharer phone, shareCode, isActive, visitorId(IP), creditedAt
  - admins: email, createdAt
- user.schema: add unique indexes on phone/wxOpenid/email; pre-save hook
  requiring at least one contact method
- user/about: add WeChat contact button (open-type=contact) for customer service

backend/src/modules/admin/admin.controller.ts

@@ -48,7 +48,7 @@ export class AdminController {
     const [
       userCount, interviewCount, todayUsers, todayInterviews,
       resumeCount, paidDownloadCount,
-      planStats,
+      planStats, orderCount, todayOrders, totalRevenue,
     ] = await Promise.all([
       this.userModel.countDocuments().exec(),
       this.interviewModel.countDocuments().exec(),
@@ -59,12 +59,19 @@ export class AdminController {
       this.userModel.aggregate([
         { $group: { _id: '$plan', count: { $sum: 1 } } },
       ]).exec(),
+      this.orderModel.countDocuments().exec(),
+      this.orderModel.countDocuments({ status: 'success', createdAt: { $gte: new Date(Date.now() - 24 * 60 * 60 * 1000) } }).exec(),
+      this.orderModel.aggregate([
+        { $match: { status: 'success' } },
+        { $group: { _id: null, total: { $sum: '$amount' } } },
+      ]).exec(),
     ])
     const planBreakdown: Record<string, number> = {}
     planStats.forEach(p => { planBreakdown[p._id || 'free'] = p.count })
     return {
       userCount, interviewCount, todayUsers, todayInterviews,
-      resumeCount, paidDownloadCount,
+      resumeCount, paidDownloadCount, orderCount, todayOrders,
+      totalRevenue: totalRevenue[0]?.total || 0,
       planBreakdown,
     }
   }
@@ -95,8 +102,8 @@ export class AdminController {
       this.interviewModel.find()
         .sort({ createdAt: -1 })
         .skip(skip).limit(+limit)
-        .populate('userId', 'phone nickname')
-        .select('position status totalScore questionCount fillerScore fillerDensity summary createdAt')
+        .populate('userId', 'phone nickname email wxOpenid')
+        .select('position status totalScore questionCount fillerScore fillerDensity summary createdAt updatedAt')
         .lean().exec(),
       this.interviewModel.countDocuments().exec(),
     ])
@@ -217,8 +224,8 @@ export class AdminController {
       this.resumeModel.find()
         .sort({ createdAt: -1 })
         .skip(skip).limit(+limit)
-        .populate('userId', 'phone nickname')
-        .select('title targetPosition version paidDownload createdAt')
+        .populate('userId', 'phone nickname email')
+        .select('title targetPosition version paidDownload createdAt updatedAt contentHash')
         .lean().exec(),
       this.resumeModel.countDocuments().exec(),
     ])

backend/src/modules/user/user.schema.ts

@@ -5,10 +5,10 @@ export type UserDocument = User & Document
 
 @Schema({ timestamps: true })
 export class User {
-  @Prop({ sparse: true })
+  @Prop({ unique: true, sparse: true })
   phone?: string
 
-  @Prop({ sparse: true })
+  @Prop({ unique: true, sparse: true })
   wxOpenid?: string
 
   @Prop({ default: '' })
@@ -60,11 +60,18 @@ export class User {
   @Prop({ default: false })
   isSystemAdmin: boolean
 
-  @Prop({ sparse: true })
+  @Prop({ unique: true, sparse: true })
   email?: string
 
   @Prop({ default: '', select: false })
   password?: string
 }
 
-export const UserSchema = SchemaFactory.createForClass(User)
+export const UserSchema = SchemaFactory.createForClass(User)
+
+UserSchema.pre('save', function (next) {
+  if (!this.phone && !this.wxOpenid && !this.email) {
+    return next(new Error('用户必须至少有一个联系方式（手机号/微信/邮箱）'))
+  }
+  next()
+})