there is no easy hard wire fix. smart bulbs would be the easiest. put an alexa in there and turn it on and off that way. you could also buy one of the "add on" remotes for ceiling fans and light fixtures to the light fixture wiring. then you could mount the remote to the wall and use it to turn the light on and off. that just requires wiring it into the top of the light fixture.

but smart bulbs would be my go to. i use them everywhere anyways.

He is right. Just make sure you clean the tub area that's your gluing too really really. Also wipe it with alcohol to make sure no residue remains for other cleaners before reglueing.

Glue it using a continuous bead of a silicone caulk. Also run a bead on the sides inside of the shower where the track meets the shower. Let dry for 24 hours before use. A bunch says you can go sooner, but if it gets touched or anything you can disform the beads you've run or even bump the track back out of place as it's not fully cured.