[Windows] Dragging to reorder tasks within a custom sidebar section removes them from the section

What version of the Codex App are you using (From “About Codex” dialog)?

26.908.4834.0, verified from the installed OpenAI.Codex Windows package.

What subscription do you have?

Not collected for this report.

What platform is your computer?

Microsoft Windows NT 10.0.26200.0

What issue are you seeing?

After moving my NEU172L lecture and Lab 3 tasks into a custom NEU172L sidebar section, dragging a task to put the tasks in chronological order takes it out of the section instead of just changing its position within the section.

This makes it difficult to organize course tasks: an attempt to reorder them changes their section membership.

What steps can reproduce the bug?

User-reported sequence:

1. Have a custom sidebar section for NEU172L.
2. Move the NEU172L lecture and Lab 3 tasks into that section.
3. Drag a task to place it in chronological order among the tasks in the same section.
4. Observe that the dragged task leaves the section instead of remaining in it at the new position.

What is the expected behavior?

Dragging a task to another position within its current section should update only its order. The task should remain a member of that section.

Additional information

• This report records the user's observed behavior. The drag interaction has not been independently reproduced during report preparation.
• The exact drop position, destination after removal, frequency, and behavior after restarting have not yet been captured.
• Related: #42165 describes custom-section ordering failing to persist through the built-in reorder tool. This report concerns manual drag-and-drop removing a task from its section, so the observed behavior differs.

Reproduce the Windows drag-and-drop sequence with two tasks in a custom NEU172L sidebar section, including the exact drop position and resulting section membership. Trace the custom-section reorder handling and verify that moving a task within its current section changes only its order and leaves it in the section.