You can get panel mount resistors. They are usually rated at way higher wattage though.

I would probably just heat shrink the resistor. Your harness should be reasonably secure anyway.

I would question why you need a 2.2ohm 1/2w resistor in a harness in the first place though.

I would say “energy harvesting” is when the receiver and transmitter are not designed to be used together and they are not physically close together. Otherwise your electric toothbrush and Qi charger might count.