Feature request: Show forked Codex threads as parent-child tree in sidebar

Summary

Please add a first-class parent/child thread view for forked Codex conversations.

When a user forks a conversation to delegate a subtask, Codex already knows the relationship internally through the source thread and child thread ids. However, the sidebar currently shows the forked thread as a normal flat conversation. Even if users rename threads with prefixes such as A and A.1, the relationship is still hard to understand at a glance.

Requested behavior

• Show forked child conversations under the parent conversation, similar to folders and subfolders.
• Allow parent conversations to expand and collapse their child conversations in the sidebar.
• Display child task status, such as running, completed, failed, or waiting for user input.
• Show a child count or latest child status on the parent conversation.
• Optionally allow users to manually group existing conversations under a parent task.

Why this matters

For larger engineering workflows, a parent conversation often coordinates several child conversations: one for code review, one for test verification, one for documentation checks, and one for risk analysis. A flat sidebar makes it hard to see which subtask belongs to which parent task, especially when several forks are active at the same time.

A tree-style parent/child view would make delegated work much easier to manage and would better match the mental model of task decomposition.

Example

Instead of a flat list:

• Parent task
• Subtask: implementation review
• Subtask: verification review

Show:

• Parent task
• Subtask: implementation review
• Subtask: verification review

This would make forked subtask ownership visible without relying on manual naming conventions.