If it were me, I'd look for something with a handgrip (however small) since I really wouldn't want to drop it. I think this rules out a phone camera. The phone is too easy to drop and too valuable to lose.
The other thing is to consider taking something that you really won't miss if it get lost, dropped or gets the sensor connections shaken to bits in a bike bag. Or gets grit in the zoom lens. This camera will have a hard life. So I'd take something that's just good enough, but inexpensive. For me this means an old camera.
So what's good enough? In my estimation, around 2006 cameras started getting good, for usable results at ISO 400, bright crisp monitors and exposure systems that worked whatever the lighting. With point and shoot cameras, Canon were a couple of years ahead of the other big manufacturers on those last two fronts. Back then, cameras offered 6MP to 8MP. This is low by modern standards, and so these cameras sell for very little. And this means you can treat them as disposable, which meets the brief for a bike tour cam.
For power, I'd look for good power consumption on the camera and a common form factor for the battery. This could mean AA batteries, or a cheaply available Li-ion battery that you can carry half a dozen of. I'd carry spare batteries rather than a charger, because in the pannier space taken up by a charger, I think you could pack enough batteries for the trip.
I might also look for
a flip out screen because these can
fold flat against the camera body to protect the monitor, making the camera more resilient in transit.
For storage of the jpegs, I'd just take a stack of cards for the camera, because that will be more space efficient than carrying a cable, assuming that uploading images can wait til you're home. Not uploading also saves battery.
I think a camera carried in a jersey pocket could be safer than one carried in a bag on the bike, because it will be somewhat isolated from the repeated impacts of a bike being ridden, since these bumps affect your own body less than your luggage. Alternatively a neoprene pouch would offer some impact protection to a camera in a handlebar bag.