feat: change answer submission logic

src/modules/submissions/entities/submission.entity.ts

@@ -12,6 +12,7 @@ import {
 import { SubmissionStatus } from '../enums/submission-status.enum';
 import { SubmissionAnswer } from './submission-answer.entity';
 import { SubmissionResult } from './submission-result.entity';
+import { Question } from '@/modules/questions/entities/question.entity';
 
 @Entity()
 export class Submission {
@@ -31,8 +32,8 @@ export class Submission {
   })
   status!: SubmissionStatus;
 
-  @Column({ type: 'int', nullable: false, default: 1 })
-  currentQuestionOrder!: number;
+  @ManyToOne(() => Question, { onDelete: 'SET NULL', nullable: true })
+  currentQuestion!: Question | null;
 
   @OneToMany(() => SubmissionAnswer, (answer) => answer.submission)
   answers!: Array<SubmissionAnswer>;