Codex Desktop should support closing current thread without archiving it

Codex Desktop currently has Command+Shift+A on macOS to archive the current thread, but I cannot find a keyboard shortcut for simply closing or dismissing the current active thread from the sidebar and returning to New Chat without archiving or deleting it.

Expected behavior:

• Command+W should close/dismiss the current thread view and return to New Chat, without archiving the thread.
• The thread should remain available in the normal recent/project chat list.
• Archive should remain a separate action, e.g. Command+Shift+A, because archiving changes the thread’s visibility/state.
• The action should be visible in the keyboard shortcuts view and searchable from the command palette.

Why this matters:

• Other agent UIs support this distinction. For example, Claude Code on macOS lets me close the current session view with Command+W without archiving it.
• In Codex, the only keyboard action I found after searching was archive, which is too heavy for “I’m done looking at this thread for now.”
• The current UI makes sidebar threads feel like browser tabs, but without the basic browser-tab close behavior.

Related but distinct:

• #24413 covers accidental immediate archive via shortcut. This request is for a non-archiving close/dismiss action.