I'd say cell phone. You will already be carrying a lot - sig stamp, stamp pads/markers, logbook, replacement supplies, water, gloves, wipes, etc. No need to add a camera to the load when you will already have a phone with you. Plus, phone cameras are so good these days - unless you are planning to enlarge your photos to far beyond standard photo album sizes, the extra resolution you get from a dedicated camera is likely unnecessary.

I think this is the first time in 6 years I've ever heard this question...

Cell phone, and make it a Samsung Galaxy. They have better camera than i Phone.

When you are letterboxing, light bags are essential. You won't want to juggle a camera AND a cell phone.

Now get out there and find a box!
😄