feat: collection model

src/service/models/collection.ts

@@ -0,0 +1,18 @@
+import { Schema, model, models, Model as MongoModel } from 'mongoose';
+import { CollectionSchema as CollectionType } from '@/types/mongoSchema';
+
+const CollectionSchema = new Schema({
+  userId: {
+    type: Schema.Types.ObjectId,
+    ref: 'user',
+    required: true
+  },
+  modelId: {
+    type: Schema.Types.ObjectId,
+    ref: 'model',
+    required: true
+  }
+});
+
+export const Collection: MongoModel<CollectionType> =
+  models['collection'] || model('collection', CollectionSchema);