No Plan canvas when using "Quick Chat"

### Short summary

No plan canvas when planning in quick chat

### Affected version or release

v0.2.27

### Installation context

Windows PC

### What happened?

When using plan mode in a quick chat to set up a new repository there was no canvas to view or comment on the plan this is something I rely heavily on and for quick chat it just wasn't there and there was sort of a general lack of canvases that were available in quick chat but most most notably was the plan canvas so I couldn't really view my plan like I can from sessions out of a repository.

### Steps to reproduce

1. Open "Quick Chat" session in the app
2. Switch to plan mode in the session text box
3. Create a plan with an AI agent
4. open the canvases pane on the left

### Expected behavior

There would be a plan canvas similar to planning sessions for repository-scoped sessions

### Additional context

_No response_

Reproduce el problema en una sesión de Windows Quick Chat usando el modo de planificación y, después, inspecciona cómo se rellena el panel de canvases para las sesiones con ámbito de repositorio en comparación con Quick Chat. La corrección está completa cuando aparece un canvas de plan y se puede ver o comentar después de que un agente de AI cree un plan en Quick Chat; verifica los pasos de reproducción existentes.

Escrito por el modelo de indexación a partir del texto del issue.