Is applying temporary plastic nails, which are removed before ablution, considered an act of "wasl" (hair extensions/artificial additions) or altering Allah's creation, and what is the difference between them and makeup?

It is not permissible to apply artificial nails except for a valid need, such as nails being affected by burns or illness. It is forbidden to apply them for adornment and excessive beautification, because this falls under changing Allah's creation and contradicts the fitra (natural disposition) of trimming nails. This is based on the Prophet's (peace and blessings be upon him) saying: "Five are from the fitra: circumcision, shaving the pubic hair, plucking the armpit hair, clipping the nails, and trimming the mustache." Changing Allah's creation is an act of Satan. As for makeup, it is permissible as long as it is not harmful.