thisisthedarshan/rastrio ? reverse-engineered prompt

Build me the first working version of this thermal printing app for Android, with the shared Kotlin code wired up so the same document can be previewed and printed consistently. I want to be able to create a simple thermal document from Markdown, lists, notes, QR codes, images, and templates, then see a preview that matches what will actually come out of an ESC POS printer.

Please make the app feel offline first and easy to use, with saved printer profiles so I can switch between different printers without redoing settings every time. Support a basic print flow for Bluetooth printers first, and keep the architecture clean so desktop can work later too. If anything is unclear, look up the current docs online and follow the project README and specs in the repo. Focus on a polished end to end experience, from editing or importing content, to previewing, to sending the job to a printer.