[DEFECT] Layout: Moving and Deleting Boxes Causes Ghosting and Broken Reflow

Problem Statement

Layout Editor where the visual state becomes desynced from the actual layout configuration. When a user moves or deletes layout boxes, "ghost" elements remain visible, and the layout flow breaks. This often results in "dead zones" where the system incorrectly perceives a space as occupied, preventing users from adding new boxes or rearranging existing ones.

Steps to Reproduce

https://github.com/user-attachments/assets/0eb1772d-544e-4b66-9827-e0553d295eb2

Acceptance Criteria

• Removing a layout box must immediately clear the UI component and update the underlying layout model.
• Moving a box must correctly recalculate the available drop zones without leaving artifact "ghosts."
• The "Add Box" functionality must remain functional and accessible in all vacated areas.
• Ensure the layout state is correctly persisted and reflected in the UI after every drag-and-drop or delete action.

dotCMS Version

main/trunk/demo

Severity

High - Major functionality broken

Start with the attached reproduction for the Layout Editor and trace the move, delete, drag-and-drop, and Add Box entry points. Reproduce the ghost elements and dead zones, then verify that removing and moving boxes update the visible UI, available drop zones, and persisted layout state.