sevenreasons/promptcat ? reverse-engineered prompt

Build me a simple prompt manager that runs as one single HTML file and works completely offline.

I want to be able to save prompts, organize them into folders, add tags, mark favorites, and quickly search through titles, bodies, notes, and tags. Everything should stay stored locally in the browser, so nothing gets sent to a server. Please make it feel clean and easy to use on both desktop and mobile, with a layout that still works well on a small screen.

It should also let me import and export my data so I can move it to another device or back it up. If possible, add a way to password protect a prompt or folder so the content is encrypted and only opens in the current session after I unlock it. I’d like bulk actions too, like selecting multiple prompts to move, delete, or export them together. A quick copy button and a character counter would be nice as well. If you need to look up current browser docs online, go for it.