AndyHazz/bookends.koplugin ? reverse-engineered prompt

Build me a KOReader plugin called Bookends that lets me add customizable text overlays on top of the reading screen.

I want to be able to place one or more lines in the six screen positions, like top left or bottom center, and have each line show things like page number, reading progress, chapter info, time, date, battery, and other reading stats. It should support simple format strings with placeholders, icons or symbols, and different styling per line. I also want a friendly editor with live preview so I can see changes right away while typing.

Please include a preset system too, so I can save my overlay layouts, rename them, edit them, duplicate them, and quickly switch between them or hide all overlays with one option. If possible, include a built in preset gallery or library view for browsing and installing presets. Make it feel polished and easy to use inside KOReader, and look up current KOReader plugin docs online if you need to.