refactor(api): split campaign workflow routers

tests/test_synchronous_delivery_policy.py

@@ -6,7 +6,8 @@ from unittest.mock import Mock, patch
 import pytest
 from fastapi import HTTPException
 
-from govoplan_campaign.backend import router
+from govoplan_campaign.backend import router as campaign_api
+from govoplan_campaign.backend.routes import delivery as router
 from govoplan_campaign.backend.delivery_policy import (
     CampaignDeliveryPolicyError,
     DEFAULT_SYNCHRONOUS_SEND_MAX_RECIPIENT_JOBS,
@@ -295,7 +296,7 @@ def test_delivery_endpoints_require_their_mode_permission_and_recipient_authorit
     path: str,
     required_scope: str,
 ) -> None:
-    route = next(item for item in router.router.routes if item.path == path)
+    route = next(item for item in campaign_api.router.routes if item.path == path)
     dependency = next(item for item in route.dependant.dependencies if item.name == "principal")
 
     with pytest.raises(HTTPException) as missing_mode_permission: