[frontend] [feature request] change swipe to next picture behavior

[fluffye-yay]

currently swiping anewhere on the screen when the picture is smaller than filling it goes to the next picture, and you cant swipe anywhere to go to the next picture when the picture is bigger.

i suggest:

1. swiping around always moves the current picture instead of changing it
2. swiping on the bottom gallery changes the picture

OR:

1. swiping on the image always moves the picture
2. swiping in the blank space around the image always changes the picture

i personally would prefer the first option as it is consistent with when there is only one image

[FireIsGood]

Currently we use Viewer.js so I am unsure if I can change these things.

[fluffye-yay]

you can get

swiping around always moves the current picture instead of changing it

by setting slideOnTouch to false (i think), not sure how to get

swiping on the bottom gallery changes the picture

or

swiping in the blank space around the image always changes the picture

do you think it is acceptable to have only the next/previous buttons & gallery to change image?

https://github.com/fengyuanchen/viewerjs?tab=readme-ov-file#slideontouch

[FireIsGood]

I'll get a pull in to try out slideOnTouch on prod on my phone.

I don't have a very strong opinion on the buttons we have at the bottom other than that they are there by default and I'm not sure if I should remove them. I could change the buttons for zooming to only be visible on wider screens. Would that seem to be better UX?

[fluffye-yay]

i dont think the zooming buttons should be based on screen size but input method... either way leaving them there isnt really a big deal & is more consistent... we really should have a set of design values for situations like this