Add dark mode toggle

src/state/models/root-store.ts

@@ -67,6 +67,7 @@ export class RootStoreModel {
       me: this.me.serialize(),
       nav: this.nav.serialize(),
       onboard: this.onboard.serialize(),
+      shell: this.shell.serialize(),
     }
   }
 
@@ -84,6 +85,9 @@ export class RootStoreModel {
       if (hasProp(v, 'onboard')) {
         this.onboard.hydrate(v.onboard)
       }
+      if (hasProp(v, 'shell')) {
+        this.shell.hydrate(v.shell)
+      }
     }
   }