text: const mongoose = require('mongoose');
  const Schema = mongoose.Schema;
  
  const AlertSchema = new Schema({
    receiver: {
      type: Schema.Types.ObjectId,
      ref: 'users',
      required: true
    },
    isRead: {
      type: Boolean,
      default: false
    },
    body: {
      type: String,
      required: true
    },
    createdAt: {
      type: Date,
      default: Date.now
    }
  });
  
  mongoose.model('alerts', AlertSchema);