work with document group

### Apache NetBeans version

Apache NetBeans 25

### What happened

I don't know if it's really aRequirement misunderstanding
or Misinterpretation of requirements or Incorrect requirements implementation or bug but it should exist Confirmation dialog or fixed list for Document Groups to prevent accidental file removal.
Thanks!

### Language / Project Type / NetBeans Component

_No response_

### How to reproduce

working with document group and close an file

### Did this work correctly in an earlier version?

No / Don't know

### Operating System

windows 10

### JDK

JDK 17

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

_No response_

### Are you willing to submit a pull request?

No

Begin by reproducing the reported behavior in the NetBeans document-group workflow: open a document group, close a file, and check whether the file is removed without confirmation. The issue does not name a source file or test; completion would require an agreed confirmation dialog or fixed-list behavior that prevents accidental file removal.

Written by the indexing model from the issue text.