Resuming a session is extremely slow, does not display UI that would indicate loading

Describe the bug

When I have several sessions in the left pane, even on the same device after restarting the CLI, resuming the session from the left pane is unbearably slow and has no loading UI. This is aggravating to use when I cannot tell if loading the session just isn't going to work at all or if it's slow. I've had it take up to a minute before.

Affected version

GitHub Copilot CLI 1.0.82

Steps to reproduce the behavior

1. Have multiple sessions present in the left pane
2. Restart CLI
3. Try to resume session, then try to resume another one
4. Notice severe delays between each of them being opened with 0 loading UI

Expected behavior

Expected sessions with fresh data to load quickly and with UX that distinguishes loading from a broken CLI

Additional context

No response

まず、CLI を再起動した後、説明されているとおり複数のセッションを使って、左ペインのセッション再開フローで遅延を再現します。再開経路を追跡し、読み込み中のフィードバックが表示されないタイミングを確認します。再開したセッションが応答しないように見えなくなり、読み込み状態と壊れた CLI を区別できるようになれば完了です。