enhance: 編集されたノートかどうか分かるように

packages/backend/src/models/Note.ts

@@ -24,6 +24,11 @@ export class MiNote {
 	})
 	public createdAt: Date;
 
+	@Column('timestamp with time zone', {
+		default: null,
+	})
+	public updatedAt: Date | null;
+
 	@Index()
 	@Column({
 		...id(),

packages/backend/src/models/json-schema/note.ts

@@ -17,6 +17,11 @@ export const packedNoteSchema = {
 			optional: false, nullable: false,
 			format: 'date-time',
 		},
+		updatedAt: {
+			type: 'string',
+			optional: true, nullable: true,
+			format: 'date-time',
+		},
 		deletedAt: {
 			type: 'string',
 			optional: true, nullable: true,
@@ -142,7 +147,7 @@ export const packedNoteSchema = {
 					isSensitive: {
 						type: 'boolean',
 						optional: true, nullable: false,
-					}
+					},
 				},
 			},
 		},