Current repeater item is lost when adding a new item in PrettyBlocks

[Daaaaad]

When editing a repeater field in PrettyBlocks (e.g. a list of ingredients), any unsaved change in the currently selected sub-item is discarded as soon as we add a new element to the repeater. The module pushes a fresh empty item to the database, reloads the whole state, and overwrites the local changes of the item we were editing.

Steps to Reproduce

• Go to Back-office → PrettyBlocks → select a zone containing a repeater block.
• Click on an existing item in the repeater list to edit it.
• Change a value, e.g. rename an ingredient. Do not click “Save”.
• Click “Add item” (➕) to append a new entry to the list.
• Observe that the name you just edited reverts to its previous value.

Expected Behavior

The current item should be auto-saved (or at least kept in memory) before inserting a new empty item, so that edits are not lost.