[Chore/Refactor] Use centralized naive_utc_now for UTC datetime operations (#24352)

Signed-off-by: -LAN- <laipz8200@outlook.com>

api/services/file_service.py

@@ -1,4 +1,3 @@
-import datetime
 import hashlib
 import os
 import uuid
@@ -18,6 +17,7 @@ from core.file import helpers as file_helpers
 from core.rag.extractor.extract_processor import ExtractProcessor
 from extensions.ext_database import db
 from extensions.ext_storage import storage
+from libs.datetime_utils import naive_utc_now
 from libs.helper import extract_tenant_id
 from models.account import Account
 from models.enums import CreatorUserRole
@@ -80,7 +80,7 @@ class FileService:
             mime_type=mimetype,
             created_by_role=(CreatorUserRole.ACCOUNT if isinstance(user, Account) else CreatorUserRole.END_USER),
             created_by=user.id,
-            created_at=datetime.datetime.now(datetime.UTC).replace(tzinfo=None),
+            created_at=naive_utc_now(),
             used=False,
             hash=hashlib.sha3_256(content).hexdigest(),
             source_url=source_url,
@@ -131,10 +131,10 @@ class FileService:
             mime_type="text/plain",
             created_by=current_user.id,
             created_by_role=CreatorUserRole.ACCOUNT,
-            created_at=datetime.datetime.now(datetime.UTC).replace(tzinfo=None),
+            created_at=naive_utc_now(),
             used=True,
             used_by=current_user.id,
-            used_at=datetime.datetime.now(datetime.UTC).replace(tzinfo=None),
+            used_at=naive_utc_now(),
         )
 
         db.session.add(upload_file)