Feature request: configurable expiration for Codex side chats

[Undertone0809]

Problem

Codex side chats currently expire after a short period. When this happens, the panel shows:

Side chat expired
This temporary side chat is no longer available; start a new side chat to continue

This is disruptive during longer code review / agent workflow sessions. A side chat often contains the precise reasoning trail, review context, and follow-up instructions for an in-progress change. If it expires too quickly, the user has to start a new side chat and manually reconstruct context.

Requested behavior

Please add a way to configure the side chat expiration duration.

Possible shapes:

• A user setting for side chat TTL, such as 1 hour / 6 hours / 24 hours / 7 days.
• A workspace or project-level setting for teams with longer review cycles.
• A "keep this side chat alive" or "pin side chat" action for important review threads.
• A warning before expiration, with an option to extend the session.

Why it matters

For short questions, temporary side chats are fine. But during real coding work, side chats are often used as lightweight, task-scoped review threads. They may need to survive breaks, long-running agent tasks, or switching between code review and implementation.

A configurable expiration would keep the temporary-chat model while letting users choose a TTL that matches their workflow.

Current workaround

Start a new side chat and restate the prior context manually, which is lossy and adds friction.