Context:
Cross-store Drag & Drop (e.g., dragging a User to a Project) can fail if both entities share the same ID (e.g., 1) but come from different stores.
With internalId (#9070), every item has a globally unique neo-record-x identifier.

Task:
Audit and update the Drag & Drop subsystems to leverage internalId for identifying dragged items.

Requirements:

1. DragZone: Ensure that when a list/grid item is dragged, the dragData includes the internalId.
2. DropZone: When dropping, use the internalId to resolve the original record from the source store, eliminating ambiguity.
3. Proxy: Ensure the drag proxy element uses a stable ID.

Scope:

• src/draggable/list/DragZone.mjs
• src/draggable/grid/DragZone.mjs
• src/draggable/DragZone.mjs