refactor: improve code formatting and organization across multiple files

backend/tests/test_repositories.py

@@ -6,6 +6,7 @@ from typing import Any, List, cast
 from uuid import uuid4
 
 import pytest
+from sqlalchemy.orm import Session
 
 from backend.app.db.models import TrainSchedule, User
 from backend.app.db.unit_of_work import SqlAlchemyUnitOfWork
@@ -23,7 +24,6 @@ from backend.app.repositories import (
     TrainScheduleRepository,
     UserRepository,
 )
-from sqlalchemy.orm import Session
 
 
 @dataclass
@@ -50,7 +50,9 @@ class DummySession:
         self.statements.append(statement)
         return self.scalar_result
 
-    def flush(self, _objects: list[Any] | None = None) -> None:  # pragma: no cover - optional
+    def flush(
+        self, _objects: list[Any] | None = None
+    ) -> None:  # pragma: no cover - optional
         return None
 
     def commit(self) -> None:  # pragma: no cover - optional
@@ -215,9 +217,7 @@ def test_unit_of_work_commits_and_closes_session() -> None:
     uow = SqlAlchemyUnitOfWork(lambda: cast(Session, session))
 
     with uow as active:
-        active.users.create(
-            UserCreate(username="demo", password_hash="hashed")
-        )
+        active.users.create(UserCreate(username="demo", password_hash="hashed"))
         active.commit()
 
     assert session.committed