fix(search): timing 로그를 setup_logger로 출력

logging.getLogger("search")만 사용하면 uvicorn 기본 설정에서 INFO가
stdout에 안 나옴. 기존 core.utils.setup_logger 패턴 사용:
- logs/search.log 파일 핸들러
- stdout 콘솔 핸들러

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

app/api/search.py

@@ -1,6 +1,5 @@
 """하이브리드 검색 API — FTS + ILIKE + 벡터 (필드별 가중치)"""
 
-import logging
 import time
 from typing import Annotated
 
@@ -12,10 +11,12 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from ai.client import AIClient
 from core.auth import get_current_user
 from core.database import get_session
+from core.utils import setup_logger
 from models.user import User
 from services.search_telemetry import compute_confidence, record_search_event
 
-logger = logging.getLogger("search")
+# logs/search.log + stdout 동시 출력 (Phase 0.4)
+logger = setup_logger("search")
 
 router = APIRouter()