Does the prohibition against approaching the mosque for those who have eaten garlic, onions, and leeks include anything with an offensive and forbidden odor, such as smoke? And is one excused from attending congregational prayer without sin if one has consumed these things?

It is disliked for someone who has eaten garlic or onions, or anything that has a foul odor, such as a smoker or someone with an offensive underarm odor, to pray with the congregation. Such a person must remove this odor. Smoking is absolutely forbidden and must be abandoned permanently.