3 - Configure permissions so submitters cannot remove records from communities

[jrcastro2]

Submitters should be able to add records to communities but not remove them. Only community curators should be able to remove records. Validate whether existing permission system supports this; implement UI adjustments if needed.

Tasks:

• Check if permission policy supports restricting record removal.
• Implement optional configuration for “submitter cannot remove record from community”.
• Ensure the UI behaves correctly (remove button only visible to curators).

Add it as invenio.cfg variable