Workcat: cute desktop cat, no window closing

Reworks the example into a pure desktop-pet: the cat wanders, sits, grooms,
stretches, dashes and naps, reacts to petting and dragging, and follows the
cursor with its eyes. The window-scanning and Accessibility code is gone.

The cat is drawn from rounded primitives plus Shape paths in a fixed 100x90
design space, so it scales cleanly to any size.

Linux/X11 is the primary target: the tray is optional, Wayland gets a warning,
and WORKCAT_X11_BYPASS / WORKCAT_OPAQUE cover uncooperative window managers.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,3 @@
+build*/
+CMakeLists.txt.user
+.DS_Store