Bug: deleting a parent session detaches its subagent sessions as standalone sessions

[thinker-shie]

Version

@agegr/pi-web 0.9.0

Steps to reproduce

1. Create a main-agent session.
2. Use the built-in subagent feature in that session to create one or more subagent sessions.
3. Return to the session list and delete the main-agent session.

Actual behavior

The main-agent session is deleted, but all subagent sessions created from it remain in the session list and are promoted to independent top-level sessions. Their parent relationship is lost.

Expected behavior

Deleting a parent session should handle its child subagent sessions consistently with the parent-child relationship. For example, Pi-web could delete the child sessions together with the parent, or show an explicit confirmation/choice to preserve and detach them. They should not silently become unrelated top-level sessions.

Additional context

This uses the built-in subagent feature included in Pi-web 0.9.0. It does not use the older third-party pi-subagent extension.

Environment

• OS: Windows 10 Pro (64-bit, 10.0.19045)
• Node.js version: v24.16.0
• Browser: Microsoft Edge 151.0.4129.93 (Official build) (64-bit)
• Installation method: installed globally via npm (@agegr/pi-web@0.9.0)

Evidence

The first screenshot shows the session list before deleting the parent session: the subagent sessions are associated with the main session.

The second screenshot shows the result after deleting the parent session: the subagent sessions remain as standalone top-level sessions.

Please see the two attached screenshots below:

• Before deletion

• After deletion