Desktop sidebar in "project" view with no project selected hides all project-less chat history

Environment

• Codex Desktop (app version 26.730.61639, core codex 0.147.0-alpha.1.2)
• Windows 11
• Project-less chats (created under the default Documents/Codex workspace)

Summary

With sidebar mode = "project" and selected-project unset/null, the left sidebar shows no
chats at all, which makes users believe their entire chat history is lost. The data is not lost:
threads are intact in state_5.sqlite (the threads table) and rollout files exist under
sessions/2026/08/.

Steps to reproduce

1. Have several project-less chats (history exists in state_5.sqlite / sessions).
2. In .codex-global-state.json, set

flat-project-sidebar-preferences-v1.mode to "project" and selected-project to null.

1. Restart Codex. The sidebar is empty; history appears gone.

Expected behavior

Project-less chats should remain visible in "project" view when no project is selected (for
example under an "All chats" fallback), or the UI should show an explanatory empty state
instead of an empty list.

Impact

Users panic and may attempt destructive recovery of data that was never lost. This also makes
config changes look like they deleted history.