Which is better: combining Maghrib and Isha prayers to perform Fajr prayer in the mosque, or performing Isha prayer in the mosque and Fajr prayer at home on weekdays, taking into account the short night and the difficulty of combining Isha and Fajr prayers in the mosque?

Congregational prayer in the mosque is, according to the preponderant opinion, obligatory for whoever hears the call. If one does not hear it due to distance, then it is not obligatory for him, though it is recommended for him to attend. If there is clear hardship in performing it at its prescribed time, along with the need for sleep and going to work, then it is permissible to combine the two prayers temporarily to remove hardship. However, this should not become a permanent habit.