fix(auth): 移除 wechat.service.ts 中对 bcrypt 的直接依赖

改用 Password VO 生成随机密码哈希，避免 TypeScript 找不到
bcrypt 类型声明的编译错误。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/auth-service/src/application/services/wechat.service.ts

@@ -31,8 +31,8 @@ import { TokenService } from './token.service';
 import { EventPublisherService } from './event-publisher.service';
 import { UserRole, UserStatus } from '../../domain/entities/user.entity';
 import { AuthResult } from './auth.service';
+import { Password } from '../../domain/value-objects/password.vo';
 import * as crypto from 'crypto';
-import * as bcrypt from 'bcrypt';
 
 @Injectable()
 export class WechatService {
@@ -109,7 +109,9 @@ export class WechatService {
     }
 
     // ── 新用户：自动注册 ──
-    const randomPasswordHash = await bcrypt.hash(crypto.randomBytes(32).toString('hex'), 10);
+    // 使用 Password VO 生成随机哈希（微信用户无需密码登录）
+    const randomPw = await Password.create(crypto.randomBytes(32).toString('hex'));
+    const randomPasswordHash = randomPw.value;
 
     const user = await this.userRepo.create({
       phone: null,