fix(conversation): use VARCHAR instead of enum for consistency with init-db.sql

- Change MessageEntity.role from enum to VARCHAR(20)
- Change MessageEntity.type from enum to VARCHAR(30)
- Change ConversationEntity.status from enum to VARCHAR(20)
- Add nullable: true to userId to match database schema
- Add length constraints to match database schema
- Convert enums to const objects with type exports for type safety

This ensures TypeORM entities match the database schema exactly,
avoiding potential issues with enum type creation in production.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/services/conversation-service/src/domain/entities/conversation.entity.ts

@@ -8,26 +8,28 @@ import {
 } from 'typeorm';
 import { MessageEntity } from './message.entity';
 
-export enum ConversationStatus {
-  ACTIVE = 'ACTIVE',
-  ENDED = 'ENDED',
-  ARCHIVED = 'ARCHIVED',
-}
+/**
+ * 对话状态常量
+ */
+export const ConversationStatus = {
+  ACTIVE: 'ACTIVE',
+  ENDED: 'ENDED',
+  ARCHIVED: 'ARCHIVED',
+} as const;
+
+export type ConversationStatusType =
+  (typeof ConversationStatus)[keyof typeof ConversationStatus];
 
 @Entity('conversations')
 export class ConversationEntity {
   @PrimaryGeneratedColumn('uuid')
   id: string;
 
-  @Column({ name: 'user_id', type: 'uuid' })
+  @Column({ name: 'user_id', type: 'uuid', nullable: true })
   userId: string;
 
-  @Column({
-    type: 'enum',
-    enum: ConversationStatus,
-    default: ConversationStatus.ACTIVE,
-  })
-  status: ConversationStatus;
+  @Column({ length: 20, default: 'ACTIVE' })
+  status: ConversationStatusType;
 
   @Column({ nullable: true })
   title: string;
@@ -35,7 +37,7 @@ export class ConversationEntity {
   @Column({ type: 'text', nullable: true })
   summary: string;
 
-  @Column({ nullable: true })
+  @Column({ length: 50, nullable: true })
   category: string;
 
   @Column({ name: 'message_count', default: 0 })

packages/services/conversation-service/src/domain/entities/message.entity.ts

@@ -8,21 +8,31 @@ import {
 } from 'typeorm';
 import { ConversationEntity } from './conversation.entity';
 
-export enum MessageRole {
-  USER = 'user',
-  ASSISTANT = 'assistant',
-  SYSTEM = 'system',
-}
+/**
+ * 消息角色常量
+ */
+export const MessageRole = {
+  USER: 'user',
+  ASSISTANT: 'assistant',
+  SYSTEM: 'system',
+} as const;
 
-export enum MessageType {
-  TEXT = 'TEXT',
-  TEXT_WITH_ATTACHMENTS = 'TEXT_WITH_ATTACHMENTS',
-  TOOL_CALL = 'TOOL_CALL',
-  TOOL_RESULT = 'TOOL_RESULT',
-  PAYMENT_REQUEST = 'PAYMENT_REQUEST',
-  ASSESSMENT_START = 'ASSESSMENT_START',
-  ASSESSMENT_RESULT = 'ASSESSMENT_RESULT',
-}
+export type MessageRoleType = (typeof MessageRole)[keyof typeof MessageRole];
+
+/**
+ * 消息类型常量
+ */
+export const MessageType = {
+  TEXT: 'TEXT',
+  TEXT_WITH_ATTACHMENTS: 'TEXT_WITH_ATTACHMENTS',
+  TOOL_CALL: 'TOOL_CALL',
+  TOOL_RESULT: 'TOOL_RESULT',
+  PAYMENT_REQUEST: 'PAYMENT_REQUEST',
+  ASSESSMENT_START: 'ASSESSMENT_START',
+  ASSESSMENT_RESULT: 'ASSESSMENT_RESULT',
+} as const;
+
+export type MessageTypeType = (typeof MessageType)[keyof typeof MessageType];
 
 @Entity('messages')
 export class MessageEntity {
@@ -32,18 +42,11 @@ export class MessageEntity {
   @Column({ name: 'conversation_id', type: 'uuid' })
   conversationId: string;
 
-  @Column({
-    type: 'enum',
-    enum: MessageRole,
-  })
-  role: MessageRole;
+  @Column({ length: 20 })
+  role: MessageRoleType;
 
-  @Column({
-    type: 'enum',
-    enum: MessageType,
-    default: MessageType.TEXT,
-  })
-  type: MessageType;
+  @Column({ length: 30, default: 'TEXT' })
+  type: MessageTypeType;
 
   @Column({ type: 'text' })
   content: string;