ENG-1495 - Split 4 sync integration (#840)

* feat(roam): add persisted canvas sync mode toggle plumbing

* feat(roam): integrate Cloudflare-backed tldraw sync store

* redo uiOverrides

* .

* undo component removal

Author: mdroidian

apps/roam/package.json

@@ -47,6 +47,7 @@
     "@tldraw/state": "2.4.6",
     "@tldraw/state-react": "2.4.6",
     "@tldraw/store": "2.4.6",
+    "@tldraw/sync": "2.4.6",
     "@tldraw/tlschema": "2.4.6",
     "@tldraw/utils": "2.4.6",
     "@tldraw/validate": "2.4.6",
@@ -80,4 +81,4 @@
     "react": "catalog:roam",
     "react-dom": "catalog:roam"
   }
-}
+}