Quoted from the Wikipedia (https://en.wikipedia.org/wiki/Vendor):

'Vendor' generally applies only to the immediate vendor, or the organization that is paid for the goods, rather than to the original manufacturer or the organization performing the service if it is different from the immediate supplier.

So, "vendedor" should be ok ;-)

I fail to follow your logic. You have provided a definition of the English term without noting that your translation is a false cognate of the original term. It makes no sense in Spanish.

Changed in several files to "fabricante", just for "hardware vendor".