[Bug]: Shared Folder with Custom Permissions Displays as "View Only"

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When sharing a folder with custom permissions (e.g., "Read & Share"), the share functions correctly, but the list of shares incorrectly displays the permissions as "View Only," causing confusion for users.

Steps to reproduce

1. Share a folder with another user using custom permissions ("Read & Share").
2. The list of shares for the share owner shows "View only"

The share itself seems to work, only the permissions are shown wrong.

https://github.com/user-attachments/assets/1ef2fa72-be70-453b-90c8-616c5a302e7a

Expected behavior

The list should display "custom permissions

Nextcloud Server version

30

No source file or test is named in the issue. Reproduce the shared-folder case with "Read & Share" and trace the share list's permission label; done when custom permissions are displayed instead of "View only" and the behavior is covered by a regression test.