presentation.sh reads $OMARCHY_PATH/logo.txt to compute LOGO_WIDTH and
LOGO_HEIGHT, which then drive max_line_width in logging.sh / errors.sh.
We were only extracting omarchy-installer into /tmp/, so logo.txt was
missing, LOGO_WIDTH=0, max_line_width=-4, and bash's substring expression
errored with 'substring expression < 0'.
Extract from omarchy-settings into the same /tmp tree so all the
presentation/logging helpers find what they expect. Renamed the dir
from omarchy-installer-iso to plain omarchy-iso since it now blends
content from two packages.