Refactor user endpoint tests to include pagination and response structure validation

- Updated tests for listing users to validate pagination and response format.
- Changed mock return values to include total count and pagination details.
- Refactored user creation mocks for clarity and consistency.
- Enhanced assertions to check for presence of pagination fields in responses.
- Adjusted test cases for user retrieval and updates to ensure proper handling of user data.
- Improved readability by restructuring mock definitions and assertions across various test files.

app/services/auth.py

@@ -454,7 +454,10 @@ class AuthService:
         return user
 
     async def change_user_password(
-        self, user: User, current_password: str | None, new_password: str,
+        self,
+        user: User,
+        current_password: str | None,
+        new_password: str,
     ) -> None:
         """Change user's password."""
         # Store user email before any operations to avoid session detachment issues
@@ -484,8 +487,11 @@ class AuthService:
         self.session.add(user)
         await self.session.commit()
 
-        logger.info("Password %s successfully for user: %s",
-                   "changed" if had_existing_password else "set", user_email)
+        logger.info(
+            "Password %s successfully for user: %s",
+            "changed" if had_existing_password else "set",
+            user_email,
+        )
 
     async def user_to_response(self, user: User) -> UserResponse:
         """Convert User model to UserResponse with plan information."""