- DragState model + drag-aware ClickHandlerView with 5pt threshold - AccessibilityBridge.moveWindow via AXUIElement kAXPositionAttribute - Floating thumbnail window follows cursor during drag - Drop centers window on target screen, patches frame locally to avoid CGWindowList race, invalidates layout engines, re-orders panels - Escape cancels drag without dismissing overlay - Visual feedback: source thumbnail at 0.3 opacity with dashed border