fix relations

api/src/entities/Expense.ts

@@ -1,4 +1,5 @@
 import { Column, CreateDateColumn, Entity, ManyToOne, OneToMany, PrimaryGeneratedColumn, UpdateDateColumn } from 'typeorm';
+import type { Relation } from 'typeorm';
 import { Category } from './Category.js';
 import { Proof } from './Proof.js';
 import { User } from './User.js';
@@ -61,11 +62,11 @@ export class Expense {
   updatedAt!: Date;
 
   @ManyToOne(() => User, (user) => user.expenses, { onDelete: 'CASCADE' })
-  user!: User;
+  user!: Relation<User>;
 
   @ManyToOne(() => Category, (category) => category.expenses, { eager: true, onDelete: 'RESTRICT' })
-  category!: Category;
+  category!: Relation<Category>;
 
   @OneToMany(() => Proof, (proof) => proof.expense, { eager: true, cascade: true })
-  proofs!: Proof[];
+  proofs!: Relation<Proof[]>;
 }