A user might move files in the file directory without JabRef.

Then, JabRef does not find the file:

But it still exists.

Example:

1. Open `test-support\src\manual-tests\issue-9798\issue-9798.bib in JabRef
2. Double click on the only entry to open the entry editor
3. Select tab "General"
4. See orange behind "minimal.pdf"
   

Normally org.jabref.gui.fieldeditors.LinkedFilesEditorViewModel#findAssociatedNotLinkedFiles is called (from org.jabref.gui.fieldeditors.LinkedFilesEditorViewModel#bindToEntry)

Task:

1. Write test in org.jabref.gui.externalfiles.AutoSetFileLinksUtilTest for this case
2. Adapt org.jabref.gui.externalfiles.AutoSetFileLinksUtil to cover the case searching for the filename (in addition to citation key logic).
3. Ensure that new logic ignores already linked files (e.g., if "minimal.pdf" is already attached to another entry)
4. Add test org.jabref.gui.externalfiles.AutoSetFileLinksUtilTest (if not already covered by 1)
5. Test in JabRef GUI

One has to ensure that "automatically search and show unlinked files" is activated