Add persisted state-machine diagram contexts and shared geometry

crates/oa-core/src/references.rs

@@ -181,6 +181,11 @@ pub fn remap_references(p: &mut Project, old: Id, new: Id) {
         });
     }
     for d in p.diagrams.values_mut() {
+        if let ProjectionKind::StateMachine { machine } = &mut d.projection
+            && *machine == old
+        {
+            *machine = new;
+        }
         for route in &mut d.routes {
             if route.edge == old {
                 route.edge = new;
@@ -280,6 +285,12 @@ fn deletion_impact_inner(p: &Project, id: Id, defer_exchange_allocations: bool)
             }
         }
         for d in p.diagrams.values() {
+            if d.projection
+                .state_machine()
+                .is_some_and(|machine| removed.contains(&machine))
+            {
+                removed.insert(d.id);
+            }
             for n in d.nodes.values() {
                 if removed.contains(&d.id) || removed.contains(&n.element) {
                     removed.insert(n.id);