Regression: sidebar hover no longer shows a Codex session’s branch

What issue are you seeing?

Previously, hovering over a session title in the sidebar showed the Git branch associated with that session. This made it easy to distinguish several parallel feature sessions without opening each conversation.

That branch information no longer appears in the hover tooltip.

Expected behavior

Hovering a project-backed session in the sidebar should show its associated Git branch, or its detached-HEAD state when applicable.

Actual behavior

The tooltip no longer exposes branch context, so identifying the correct session requires opening it and checking its header or Git controls.

Why this matters

When several feature branches are active, concise session titles alone are insufficient. The missing branch context makes parallel work easier to confuse and slows navigation.

Related issues

• #40203 requests richer sidebar-hover details, though it focuses on task summaries.
• #22130 requests worktree/branch visibility in the bottom status area.

This report is specifically about restoring the Git branch in the sidebar session-title hover tooltip.

Start by locating the sidebar session-title hover tooltip implementation and trace how project-backed sessions expose Git context. Reproduce the regression with a session linked to a branch and with detached HEAD, then verify the tooltip shows the branch or detached-HEAD state without opening the session.