feat: add notification data model and migration

myteamwallet_backend/src/notifications/entities/notification-recipient.entity.ts

@@ -0,0 +1,23 @@
+import { Column, Entity, Index, ManyToOne, PrimaryGeneratedColumn } from 'typeorm';
+import { EntityHelper } from 'src/utils/entity-helper';
+import { Notification } from './notification.entity';
+
+@Entity()
+export class NotificationRecipient extends EntityHelper {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Index('IDX_notification_recipient_notification_id')
+  @ManyToOne(() => Notification, { onDelete: 'CASCADE' })
+  notification: Notification;
+
+  @Index('IDX_notification_recipient_user_id')
+  @Column()
+  userId: number;
+
+  @Column({ default: false })
+  read: boolean;
+
+  @Column({ nullable: true })
+  readAt: Date | null;
+}