What is the criterion for movement in prayer, and what is the ruling on dhikr (remembrance of God) during the recitation of Surat Al-Fatiha, such as praising God upon sneezing or saying “Bismillah” (in the name of God) when swallowing saliva, especially for one who suffers from obsessive-compulsive disorder (waswās)?

Reciting Al-Fatiha is not interrupted by minor remembrance like saying "Bismillah" (In the name of Allah) or "Alhamdulillah" (Praise be to Allah). However, if such remembrance becomes frequent, one should restart its recitation, unless silence is commanded. Saying "Bismillah" is not legislated when swallowing saliva. The cure for obsessive whispers (waswas) is to ignore them.