[New Feature]: Mask known stars from detection in subtraction

[wmwv]

Is your feature request related to a problem? Please describe.

Current detection finds artifacts from bright stars.

Describe the solution you'd like

Use image pixel mask to reject sources near bright stars. Track effective area.

Describe alternatives you've considered

Use a star catalog. Could work fine as well, a bit dependent on the source-extract processing, but I think the image pixel mask is actually generated this way anyway right now.

Additional context