feat: add import routes and ingestion service for project and scenario imports

dependencies.py

@@ -21,6 +21,7 @@ from services.session import (
     extract_session_tokens,
 )
 from services.unit_of_work import UnitOfWork
+from services.importers import ImportIngestionService
 
 
 def get_unit_of_work() -> Generator[UnitOfWork, None, None]:
@@ -30,6 +31,15 @@ def get_unit_of_work() -> Generator[UnitOfWork, None, None]:
         yield uow
 
 
+_IMPORT_INGESTION_SERVICE = ImportIngestionService(lambda: UnitOfWork())
+
+
+def get_import_ingestion_service() -> ImportIngestionService:
+    """Provide singleton import ingestion service."""
+
+    return _IMPORT_INGESTION_SERVICE
+
+
 def get_application_settings() -> Settings:
     """Provide cached application settings instance."""