IceManateeKnit/email-pass-checker-utility ? reverse-engineered prompt

Build me a small Windows desktop app that lets me load a text or CSV file with email and password pairs, checks the data locally, and shows me which rows are valid, malformed, duplicated, or skipped.

I want it to feel simple and fast, with a clear progress view while it runs, a clean results screen, and easy export to CSV or TXT when it is done. It should handle big lists without needing any internet connection, and it should not try to sign in anywhere, just validate the structure and consistency of the pairs. Please include support for changing the delimiter, basic custom rules for what counts as valid, and a history of recent scans so I can compare runs later.

Make it look polished, with dark and light themes, and keep it easy enough that someone can just unzip it and run it on Windows 10 or 11. If you need to, look up current docs online for the best way to package a simple standalone Windows app.