refactor(tests): replace crud references with repo across repository test files

- Updated import statements and test logic to align with `repositories` naming changes.
- Adjusted documentation and test names for consistency with the updated naming convention.
- Improved test descriptions to reflect the repository-based structure.

backend/tests/e2e/test_admin_workflows.py

@@ -46,7 +46,7 @@ async def login_user(client, email: str, password: str = "SecurePassword123!"):
 
 async def create_superuser(e2e_db_session, email: str, password: str):
     """Create a superuser directly in the database."""
-    from app.repositories.user import user_repo as user_crud
+    from app.repositories.user import user_repo as user_repo
     from app.schemas.users import UserCreate
 
     user_in = UserCreate(
@@ -56,7 +56,7 @@ async def create_superuser(e2e_db_session, email: str, password: str):
         last_name="User",
         is_superuser=True,
     )
-    user = await user_crud.create(e2e_db_session, obj_in=user_in)
+    user = await user_repo.create(e2e_db_session, obj_in=user_in)
     return user