Bionus/imgbrd-grabber — reverse-engineered prompt

Build me a cross platform imageboard downloader app called Grabber. I want a simple desktop app for Windows, Mac, and Linux that can search booru style sites like Danbooru and Gelbooru, show results from one or more sources in tabs, hide duplicates, and help with tag search using autocomplete, blacklists, saved favorites, and view later searches. It should be able to download single posts by ID or MD5, or bulk download thousands of images at once, with optional auto download while browsing.

The big thing I care about is organizing files well. Let users choose a save folder and custom filename patterns based on image info like artist, character, copyright, md5, and extension, plus conditional naming and renaming already downloaded files. Please include support for proxies, login protected sources, adding custom sources, themes, and a basic command line mode for downloads too. If the project docs already cover install and build steps, follow those and look up current docs online if you need to.