IMAGEADJUST: Image Adjust dialog for raster images

IMAGEADJUST (alias IAD) takes the selected raster images or asks
"Select image(s):", then opens a dialog with a before/after preview of
the first image and brightness, contrast and fade rows (bar plus
stepper, whole numbers 0-100). Apply writes the values to every chosen
image as one undo step; restore defaults sets 50/50/0. Adds the
image_adjust automation action and the image-adjust locale group.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

assets/ocad.pgp

@@ -74,6 +74,7 @@ XR,       *XREF
 -XR,      *-XREF
 XC,       *XCLIP
 ICL,      *IMAGECLIP
+IAD,      *IMAGEADJUST
 ADC,      *ADCENTER
 W,        *WBLOCK