Is it permissible, in Islamic law, for me to marry a woman while not being counted among the treacherous or the unjust in the sight of Allah, given that she is unaware of an incident that occurred in my childhood—namely, that I was subjected to sexual assault (rape) as a child—and I am unable to disclose it to anyone as long as Allah has concealed it?

There is no objection to your marrying any girl as long as you are able to fulfill her material and physical rights and you do not have a sexual disability. You are not required to inform her of what happened to you in your childhood. Conceal yourself as Allah has concealed you, and hasten to marry to protect your chastity and to obey the Prophet's ﷺ call. Forget what happened to you in your childhood, as it will only bring worry and anxiety.