Is working as a financial manager in a company that sells tight, short, and transparent women's clothing, deals with Riba (usury/interest), and provides commercial insurance, considered permissible (halal) or forbidden (haram)? And if it is forbidden, is it obligatory to leave the job immediately, or can one continue working until another job is found?

There is no harm in working for a company whose work is permissible, unless the employee's work is directly related to something forbidden or assists in it. Since your work involves writing financial reports that include usurious statements, and following up on and settling forbidden insurance contracts, it is not permissible for you to continue in it because you are directly involved in forbidden work and assisting in it. It is narrated from Jabir that the Prophet, may Allah's peace and blessings be upon him, cursed the one who consumes usury, the one who gives it, its scribe, and its two witnesses, and he said: "They are all equal." This includes everyone who is involved with usury through writing or reviewing. You must abandon these tasks immediately, and if you are not transferred to another permissible job, then you must leave the job and seek lawful work, for whoever gives up something for the sake of Allah, Allah will compensate him with something better, and Allah's provision is abundant. As for selling women's clothing and other items that may be used for lawful or unlawful purposes, the basic principle is that it is permissible to sell them, except to one who is known or it is highly probable that they will use them for unlawful purposes. Your main problem lies in the usurious and insurance contracts that you are directly involved in.