Photoshop Batch Background Script

I have a folder full of JPEG shots that all need the same treatment: drop the existing backdrop, replace it with a clean white one, flatten, and write the result out as a new JPEG into a second folder while keeping the original file names intact.

I would like a single, self-contained Photoshop JavaScript/ExtendScript (.jsx) that will:
• Loop through every .jpg in the source directory I point it to
• Use Photoshop’s built-in Remove Background command (the same routine accessed from the Properties panel) to isolate the subject
• Add a solid white layer beneath, merge or flatten so no transparency remains
• Save the output as a JPEG (quality 10 or higher) into the destination directory under the exact same name, leaving the originals untouched

Please code it so the two paths (input and output) are easy to change at the top of the file, and so it runs cleanly on both macOS and Windows installations of the latest Photoshop. A short comment block explaining usage and any required preferences is all I need for documentation.

Deliverables
1. The .jsx script file
2. Brief instructions for loading and running it in Photoshop (File → Scripts → Browse or via the Scripts panel)

I can test on my side and confirm once a full batch runs without errors and every image shows a white background with no stray pixels. Looking forward to your solution!