Drive File Auto-Organizer Script

I want a Google Apps Script that automatically files the contents of my Google Drive without any manual intervention. The script should watch my Drive, detect new or existing files, and move (or copy, if you think that is safer) each item into the correct sub-folder using clear, logical rules—think file type, keywords in the filename, or date. I am happy to discuss and refine the exact logic with you so it matches the way I work.

Please write the code directly in Apps Script, comment it thoroughly, and set up an installable trigger so the filing happens on its own. Once the script is complete, I need a short set-up guide and a quick walk-through to be sure everything is connected correctly in my account. A round of tweaks after my first live test is also part of the scope.