fix: job_queue 모듈 import 방식 수정 — None 참조 해결

모듈 레벨 변수를 직접 import하면 init_queue() 이후에도
None 참조가 유지됨. 모듈 자체를 import하여 접근.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

nanoclaude/main.py

@@ -13,7 +13,7 @@ from config import settings
 from db.database import init_db
 from routers import chat
 from services.backend_registry import backend_registry
-from services.job_queue import init_queue, job_queue
+from services import job_queue as jq_module
 
 logging.basicConfig(
     level=logging.INFO,
@@ -26,7 +26,7 @@ async def lifespan(app: FastAPI):
     await init_db()
     backend_registry.init_from_settings(settings)
     backend_registry.start_health_loop(settings.health_check_interval)
-    init_queue(settings.max_concurrent_jobs)
+    jq_module.init_queue(settings.max_concurrent_jobs)
     yield
     backend_registry.stop_health_loop()
 
@@ -66,9 +66,8 @@ async def root():
 
 @app.get("/health")
 async def health():
-    from services.job_queue import job_queue
     return {
         "status": "ok",
         "backends": backend_registry.health_summary(),
-        "queue": job_queue.stats if job_queue else {},
+        "queue": jq_module.job_queue.stats if jq_module.job_queue else {},
     }