fix ts errors in various files

src/models/attachment.js

@@ -3,6 +3,12 @@ import UserModel from './user'
 import FileModel from './file'
 
 export default class AttachmentModel extends AbstractModel {
+	id = 0
+	taskId = 0
+	file = FileModel
+	createdBy = UserModel
+	created = null
+
 	constructor(data) {
 		super(data)
 		this.createdBy = new UserModel(this.createdBy)

src/models/subscription.js

@@ -2,6 +2,12 @@ import AbstractModel from '@/models/abstractModel'
 import UserModel from '@/models/user'
 
 export default class SubscriptionModel extends AbstractModel {
+	id = 0
+	entity = ''
+	entityId = 0
+	created = null
+	user = UserModel
+
 	constructor(data) {
 		super(data)
 		this.user = new UserModel(this.user)

src/models/task.js

@@ -10,7 +10,11 @@ import {parseDateOrNull} from '@/helpers/parseDateOrNull'
 const SUPPORTS_TRIGGERED_NOTIFICATION = 'Notification' in window && 'showTrigger' in Notification.prototype
 
 export default class TaskModel extends AbstractModel {
-
+	index = 0
+	done = false
+	priority = 0
+	percentDone = 0
+	
 	defaultColor = '198CFF'
 
 	constructor(data) {