Is it permissible to work in the industry of making beaded hair threads for hair adornment, and is this considered among the accursed وصلة (hair extensions) mentioned in the Hadith: "May Allah curse the woman who affixes hair extensions and the one who asks for them to be affixed"?

It is likely permissible to extend hair with something other than human hair, such as colored silk threads or wool, provided it does not resemble human hair. What is forbidden is the extension of hair with hair, due to the deception involved. Imam Ahmad used to permit qaramel, which are silk or wool threads braided and used by women to extend their hair.