Knob sizing calls Stringify for every value from Min to Max. If the
computed span exceeds MUI_MAXMAX it instead scans zero through
MUI_MAXMAX, which can miss wide strings for the real range.
CheckAllSizes is ignored by this scan. Signed span/loop arithmetic is
unchecked; a maximum at LONG_MAX can overflow the loop increment.
Draw maps Value to pixel offset and caches both offset and a copied
Stringify result. Text-copy allocation is unchecked before strlen. Setup
does not turn knob-background preparation failure into FALSE. Mouse
handling requires geometry established by drawing and a nonnegative
travel length.
A non-shift click on the knob starts dragging and sets Pressed. A
background click changes Value by one with Reverse honored. A later
non-SELECTDOWN button event ends a pressed drag. Mouse moves map offset
through ScaleToValue on a zero-based scale and use the Numeric setter
directly to preserve pixel offset. Notifications remain enabled even in
Quiet mode.