dimsemenov/PhotoSwipe ? reverse-engineered prompt

Build me a JavaScript photo gallery and lightbox that works nicely on both mobile and desktop, with the same smooth feel as PhotoSwipe. I want it to be framework independent, easy to drop into a plain site, and modular enough that the gallery and lightbox parts can be used on their own if needed.

Please include a simple demo page and clear setup instructions, plus a few examples showing how to open images, navigate between them, and handle things like captions and thumbnails. Make it feel polished, fast, and touch friendly, with keyboard support too. If you need to check the latest docs or patterns online, go ahead and do that.

I’d also like the code organized cleanly so it’s easy to build from source into a dist folder, and easy to tweak later if I want to add more docs or test pages.