Describe the bug
Images without WCS do not display in the correct aspect ratio

b1509_xray_nowcs.fits.zip

To Reproduce
Steps to reproduce the behavior:

1. Open b1509_xray_nowcs.fits
2. See the aspect ratio is not 1:1 but follows that of the window

Expected behavior
The aspect ratio should be 1:1.

Screenshots or videos

Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: macOS Sequoia 15.5
• Browser [e.g. chrome, safari, electron app]: chrome
• Browser version [e.g. 22]: 140.0.7339.80
• Backend branch [e.g. dev, v3b2 release]: dev, 5.0.3
• Frontend branch [e.g. dev, v3b2 release]: dev, 5.0.3