Sync terminal title with thread name, and update it immediately on rename

What variant of Codex are you using?

Codex CLI in a terminal emulator that uses the terminal title for tab labels. (Kitty terminal).

### What feature would you like to see?

Codex should sync the terminal title with the current thread name.

Specifically:

1. When a thread first gets a name, Codex should update the terminal title.
2. When the thread is renamed later, Codex should immediately update the terminal title again.
3. The visible terminal/tab title should stay aligned with the current thread name for that active session.

### Expected behavior

• A newly named thread updates the terminal title automatically.
• Renaming the thread updates the terminal title immediately, without restarting Codex.
• The same thread name should be reflected consistently in session/thread UI and in the terminal title.

### Why this matters

In terminal workflows, the terminal title is often what shows up as the tab title. This helps keep multiple concurrent workflows organized and gives developers simpler visual context in their terminal tabs.

For example, in Kitty, I use the terminal title as the tab label. That makes thread naming much more useful if Codex also pushes the thread name into the terminal title and keeps it updated on rename.

Claude Code already does this, and it makes terminal tabs much easier to scan.

### Related issues

This is closely related to, but distinct from:

• #24289 (https://github.com/openai/codex/issues/24289): auto-generate and apply a concise thread name after the first prompt
• #14482 (https://github.com/openai/codex/issues/14482): allow setting thread name at session start with codex --name
• #24060 (https://github.com/openai/codex/issues/24060): auto-updating titles as the conversation changes
• #15444 (https://github.com/openai/codex/issues/15444): assistant-invokable rename

Those are about how the thread gets named. This request is about syncing that name to the terminal title so terminal tabs stay useful.