rubenalfon/Pile ? reverse-engineered prompt

Build me an Android app called Pile for managing personal documents in one place.

I want a clean, modern app where people can add, view, edit, search, and organize files with tags, which you can call piles. It should feel polished and easy to use, with a strong focus on document detail screens, editing, and a smooth home view. Include local storage so documents and tags are saved on the device, and make search fast and useful. It should support PDF files and basic sharing and import flows too.

Use a modern Compose based UI with Material 3 styling, and keep the app structured so it stays easy to maintain as it grows. I’d like the state handled in a reactive way, with clear separation between UI, business logic, and data. If you need to check current Android or library docs while building it, feel free to look them up online.