Add Feature: Ability to either overlay custom image overlay as a border or set a border color on the frame.

[andrewamason]

Description

Add the option to set a custom border image/color around the outside of the images on the frame.

Use Case

With ImmichFrame running on larger screens such as TVs it would be nice to be able to add a border color or the ability to set an overlay image around the outside of the image to set it off of the actual TV bezel.

Details

This is a really popular feature of some YouTube TV frame videos this would let users customize the look of their frame to match the style they are trying to achieve with the ImmichFrame App.

The most feature rich option would be the ability to overlay something like a transparent .png image scaled around the outside of the frame, however I'm not sure how that would even work. A color customizable border would still be a good option though if the image overlay is too difficult to implement.

Pre-Submission Checklist

• This is a feature request and not a bug report

• I have checked for related issues and checked the documentation