Do not disable "Scale to Fit" after a manual zoom

Windows OS version

Windows 11 24H2

ImageGlass version

v9.3.2.520

ImageGlass release

Classic

1️⃣ Describe the feature

"Scale to Fit" syncs image zoom level with the ImageGlass window size. However, if you turn on this feature and then manually zoom, it effectively disables "Scale to Fit" functionality. I would like it to persist through manual zoom commands.

This is easier for me to explain with a video:

https://github.com/user-attachments/assets/e685932d-fd97-479a-8ed9-9780053a882f

I would like the image to continue shrinking or expanding with the window even after the manual zoom change. I hope that makes sense. 😅

Programmatically, I would expect Scale to Fit to "kick back on" if the window is resized such that the image can no longer fit within the window.

2️⃣ How to use feature

I imagine it would be best to implement this as an option in Settings > Image or Settings > Viewer.

3️⃣ Additional context

N/A

Start by reproducing the current Scale to Fit and manual zoom behavior in the Classic viewer on Windows 11, then trace the viewer's zoom and window-resize handling. Determine where the existing behavior disables Scale to Fit and how a Settings option would fit the requested workflow. Done means the image continues responding to window resizing after manual zoom, with the behavior covered by the relevant tests.