fix: TS 类型错误 — itIfInfra 签名 + logger 声明位置

- itIfInfra: () => Promise<void> → () => void | Promise<void>（兼容同步测试）
- AiJobService.logger: 移至 class 顶部，消除方法调用前未声明问题

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

src/modules/ai-job/ai-job.service.ts

@@ -8,6 +8,8 @@ import { JobNotCancellableError } from './ai-job.errors';
 
 @Injectable()
 export class AiJobService {
+  private readonly logger = new (require('@nestjs/common').Logger)(AiJobService.name);
+
   constructor(
     private readonly prisma: PrismaService,
     private readonly lifecycleRepo: AiJobLifecycleRepository,
@@ -189,7 +191,6 @@ export class AiJobService {
     return this.toAdminResponse(newJob);
   }
 
-  private logger = new (require('@nestjs/common').Logger)(AiJobService.name);
 
   // ── 可观测性 ──
 

test/m-ai-03-synthetic.e2e-spec.ts

@@ -97,7 +97,7 @@ describe('M-AI-03 Synthetic E2E (real infra)', () => {
   });
 
   // Guard: skip all tests if infra not available
-  const itIfInfra = (name: string, fn: () => Promise<void>) => {
+  const itIfInfra = (name: string, fn: () => void | Promise<void>) => {
     it(name, async () => {
       if (!infraAvailable) {
         console.log(`  [SKIP] Infra unavailable: ${name}`);