feat: implement QuestionBank CRUD with pagination and template query

- Add pagination support to findAll (page, limit query params)
- Add findByTemplateId method to service
- Add GET /by-template/:templateId endpoint to controller
- Service already includes CRUD for QuestionBank and QuestionBankItem

server/src/assessment/entities/assessment-session.entity.ts

@@ -0,0 +1,106 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  UpdateDateColumn,
+  ManyToOne,
+  JoinColumn,
+  OneToMany,
+} from 'typeorm';
+import { User } from '../../user/user.entity';
+import { KnowledgeBase } from '../../knowledge-base/knowledge-base.entity';
+import { KnowledgeGroup } from '../../knowledge-group/knowledge-group.entity';
+import type { AssessmentQuestion } from './assessment-question.entity';
+import { AssessmentTemplate } from './assessment-template.entity';
+
+export enum AssessmentStatus {
+  IN_PROGRESS = 'IN_PROGRESS',
+  COMPLETED = 'COMPLETED',
+}
+
+@Entity('assessment_sessions')
+export class AssessmentSession {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ name: 'user_id' })
+  userId: string;
+
+  @ManyToOne(() => User)
+  @JoinColumn({ name: 'user_id' })
+  user: User;
+
+  @Column({ name: 'tenant_id', nullable: true })
+  tenantId: string;
+
+  @Column({ name: 'knowledge_base_id', nullable: true })
+  knowledgeBaseId: string | null;
+
+  @ManyToOne(() => KnowledgeBase, { nullable: true })
+  @JoinColumn({ name: 'knowledge_base_id' })
+  knowledgeBase: KnowledgeBase;
+
+  @Column({ name: 'knowledge_group_id', nullable: true })
+  knowledgeGroupId: string | null;
+
+  @ManyToOne(() => KnowledgeGroup, { nullable: true })
+  @JoinColumn({ name: 'knowledge_group_id' })
+  knowledgeGroup: KnowledgeGroup;
+
+  @Column({ name: 'thread_id', nullable: true })
+  threadId: string;
+
+  @Column({
+    type: 'varchar',
+    enum: AssessmentStatus,
+    default: AssessmentStatus.IN_PROGRESS,
+  })
+  status: AssessmentStatus;
+
+  @Column({ type: 'float', name: 'final_score', nullable: true })
+  finalScore: number;
+
+  @Column({ type: 'text', name: 'final_report', nullable: true })
+  finalReport: string;
+
+  @Column({ type: 'simple-json', nullable: true })
+  messages: any[];
+
+  @Column({ type: 'simple-json', name: 'feedback_history', nullable: true })
+  feedbackHistory: any[];
+
+  @Column({ type: 'int', name: 'current_question_index', default: 0 })
+  currentQuestionIndex: number;
+
+  @Column({ type: 'int', name: 'follow_up_count', default: 0 })
+  followUpCount: number;
+
+  @Column({ type: 'simple-json', nullable: true })
+  questions_json: any[];
+
+  @Column({ type: 'varchar', length: 10, default: 'zh' })
+  language: string;
+
+  @Column({ name: 'template_id', nullable: true })
+  templateId: string;
+
+  @ManyToOne(() => AssessmentTemplate, { nullable: true })
+  @JoinColumn({ name: 'template_id' })
+  template: AssessmentTemplate;
+
+  @Column({ type: 'simple-json', name: 'template_json', nullable: true })
+  templateJson: any;
+
+  @OneToMany(
+    'AssessmentQuestion',
+    (question: AssessmentQuestion) => question.session,
+  )
+  questions: AssessmentQuestion[];
+
+  @CreateDateColumn({ name: 'created_at' })
+  createdAt: Date;
+
+  @UpdateDateColumn({ name: 'updated_at' })
+  updatedAt: Date;
+}