refactor(notes): scope stacked-note sticky to desktop

Move position: sticky from the global .note rule into the desktop
@media block of the scoped stacked-note components, so mobile no longer
inherits sticky positioning (and no top is set there).

src/views/PublicNoteView.vue

@@ -241,7 +241,6 @@ watch(
     overflow-y: auto;
     height: 100vh;
     width: 100%;
-    position: sticky;
 
     .title {
       text-align: left;