Window detection was broken by wrong CG-to-AppKit coordinate conversion
of the cursor and highlight rects — both now go through the same
cgToAppKit mapping. The draw toolbar gains a Pen/Redact toggle: redact
drags cover content with a solid black bar (participates in undo/redo
and export like pen strokes).
💘 Generated with Crush
Assisted-by: Crush:deepseek-v4-flash-0731
Hovering during selection now highlights the window under the cursor;
clicking captures it with a rounded-corner alpha mask matching macOS
window chrome. Dragging still switches to manual marquee selection.
💘 Generated with Crush
Assisted-by: Crush:deepseek-v4-flash-0731
TZGyn