Can you delete the Mudita stock Calendar, Meditation and Music apps? I don’t think you can, at least not without a lot of risky tech-level furtling about with adb.
Also, although you can manually stop background running Mudita stock apps like Calendar, they will automatically restart on device reboot (and possibly other times too; I’m not clear on that).
I understand from this forum that this will be addressed in Mudita OS v2.0 (autumn 2026).