なんかもうめっちゃ変えた

packages/backend/src/models/entities/PromoNote.ts

@@ -0,0 +1,28 @@
+import { PrimaryColumn, Entity, Index, JoinColumn, Column, OneToOne } from 'typeorm';
+import { id } from '../id.js';
+import { Note } from './Note.js';
+import type { User } from './User.js';
+
+@Entity()
+export class PromoNote {
+	@PrimaryColumn(id())
+	public noteId: Note['id'];
+
+	@OneToOne(type => Note, {
+		onDelete: 'CASCADE',
+	})
+	@JoinColumn()
+	public note: Note | null;
+
+	@Column('timestamp with time zone')
+	public expiresAt: Date;
+
+	//#region Denormalized fields
+	@Index()
+	@Column({
+		...id(),
+		comment: '[Denormalized]',
+	})
+	public userId: User['id'];
+	//#endregion
+}