Tooling and app should compile and run when no components are found

## Background
The tooling was created in Toolkit Labs, and was created using CanvasLayout as our testing ground. The tooling has only ever been used with at _least_ one component present.

## Problem
The tooling fails in some places when no components are found. This manifests in various forms.

## Solution
This issue documents and tracks the various problems we've found when no components are present. See comments below.

Commencez par reproduire les outils et l’application sans aucun composant présent, puis consultez les commentaires de l’issue concernant les points d’échec documentés. C’est terminé lorsque les outils et l’application se compilent et s’exécutent correctement lorsqu’aucun composant n’est trouvé.

Rédigé par le modèle d'indexation à partir du texte de l'issue.