Add comprehensive tests for mentor repository and authentication

- Implemented tests for creating, retrieving, updating, and deleting mentors in `mentor_repository_test.rs`.
- Added tests for user authentication, including successful login, invalid email formats, and inactive users in `auth_login_tests.rs`.
- Created a mock test environment setup in `mock_test.rs` to facilitate database operations during tests.
- Updated module structure to include new test files for mentors and authentication.
- Ensured cleanup of the database after tests to maintain isolation and prevent side effects.

imphnen-backend/src/main.rs

@@ -3,6 +3,8 @@ use imphnen_libs::axum_init;
 
 #[tokio::main]
 async fn main() {
+	tracing_subscriber::fmt::init();
+
 	axum_init(|surrealdb_ws, surrealdb_mem| async {
 		gateway_service(surrealdb_ws, surrealdb_mem).await
 	})