feat: Add physics model design document, implement multi-card snapping and layout system improvements, and refine pointer event handling.

frontend/src/styles/workspace/workspace-cards.css

@@ -15,6 +15,10 @@
   overflow: hidden;
 }
 
+.desk-item--swoop {
+  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
+}
+
 .desk-item__card img {
   width: 100%;
   height: 100%;