Overlays don't render when switching documents

[0HyperCube]

To reproduce:

• Open https://dev.graphite.rs/
• Create a new document with an artboard
• Create another new document with an artboard.
• Switch back to the first document
• Observe that the overlay for the artboard name is no longer there. This also applies to tools with overlays (e.g. the select tool doesn't have any overlays).
• Switch tools and observe that overlays return.