UI: hidden freights are included in drag and drop

[Marvin9]

Checklist

• I've searched the issue queue to verify this is not a duplicate bug report.
• I've included steps to reproduce the bug.
• I've pasted the output of kargo version.
• I've pasted logs, if applicable.

Description

Dragging the freight right after hidden freight includes the hidden freight when dragging

Screenshots

Screen.Recording.2025-10-10.at.12.35.21.PM.mov

Steps to Reproduce

Check the video

Version

dev

Logs

Paste any relevant application logs here.