fix(audit): centraliser l'horloge UTC

app/routes/users/contracts.py

@@ -2,7 +2,6 @@
 
 import os
 import uuid
-from datetime import datetime
 
 from flask import flash, redirect, render_template, request, send_file, url_for
 from flask_babel import gettext as _
@@ -20,6 +19,7 @@ from app.routes.users._shared import (
 )
 from app.routes.users.blueprint import users_bp
 from app.storage import CONTRACTS_DIR, document_path
+from app.time_utils import utc_now_naive
 from app.validators import UploadContractSchema
 
 
@@ -172,7 +172,7 @@ def upload_signed_contract(contract_id):
     contract.signed_filename = signed_filename
     contract.signed_file_path = signed_path
     contract.status = 'signed'
-    contract.signed_at = datetime.utcnow()
+    contract.signed_at = utc_now_naive()
     db.session.commit()
     flash(_('Signed contract uploaded successfully!'), 'success')
     return redirect(url_for('users.list_contracts'))