Hello,
I absolutely love your project! Thank you.

I added a password protection feature - it's not a real login feature (with users management), just the ability to set a password before viewing the contents of folders.
If the hashed_password variable is empty or not present the script works as usual, without any request for a password.

I also reduced the icon_url variable: I prefer to put the flat.png file in the same folder as the script. This seems to me a simple and minimal approach, in line with the nature of the project. Why complicate life? 😉

I hope the code quality is decent, I am not a pro developer in PHP.