Feature request: VS Code Codex pane should keep the session list visible alongside the open chat

Feature request for the Codex VS Code extension.

The Codex VS Code extension should allow the session list to remain visible alongside the currently open Codex chat, with fast switching between sessions.

Today, once a Codex session is open, switching to another session requires leaving the active chat flow and using separate recent/history affordances. This makes session management feel detached from the main workflow.

Desired behavior:

• The Codex pane can show a session list and the active chat at the same time.
• Selecting a session from the list switches the active chat quickly.
• The session list remains visible after switching sessions.
• There is a clear new-session action in the same pane.
• Sessions are sorted by last updated time by default.

Why this is useful:

For users working with multiple Codex sessions, the session list is not just archive/history. It is part of the active workflow. Keeping the list visible beside the open chat makes it easier to move between ongoing implementation, review, debugging, and planning threads without losing context.

This would bring the Codex extension closer to the ergonomics of VS Code’s built-in Copilot Chat session UI while preserving the direct Codex extension experience.

Additional information:

Related issues:

• #12098: Tabbed interface for parallel chat sessions in Codex extension
• #19603: VS Code extension session sidebar should match Codex CLI resume picker semantics
• #15368: Increase cap of sessions in VS Code extension
• microsoft/vscode#300191: Sessions with Codex are set as unread sessions

This request is related to #12098, but distinct. #12098 asks for tabs as the switching mechanism. This issue is specifically asking for a persistent session list next to the active chat, matching the session-list + active-chat workflow used by VS Code Copilot Chat.

Non-goals for this request:

• tabs
• full history redesign
• advanced search
• pinned sessions
• pagination changes
• billing/authentication changes
• exact visual parity with Copilot