Add function to sync trigger volume flags after mutation

src/app/App.tsx

@@ -1550,6 +1550,36 @@ export function App({ store, initialStatusMessage }: AppProps) {
     setStatusMessage(successMessage);
   };
 
+  // After any link mutation on a trigger volume, re-derive and persist the
+  // triggerOnEnter/triggerOnExit flags so the document stays consistent.
+  const syncTriggerVolumeFlags = (sourceEntityId: string, linksAfterMutation: InteractionLink[]) => {
+    const entity = editorState.document.entities[sourceEntityId];
+    if (entity?.kind !== "triggerVolume") return;
+
+    const triggerOnEnter = linksAfterMutation.some((l) => l.trigger === "enter");
+    const triggerOnExit = linksAfterMutation.some((l) => l.trigger === "exit");
+
+    if (entity.triggerOnEnter === triggerOnEnter && entity.triggerOnExit === triggerOnExit) return;
+
+    try {
+      const nextEntity = createTriggerVolumeEntity({
+        id: entity.id,
+        position: entity.position,
+        size: entity.size,
+        triggerOnEnter,
+        triggerOnExit
+      });
+      store.executeCommand(
+        createUpsertEntityCommand({
+          entity: nextEntity,
+          label: "Sync trigger volume flags"
+        })
+      );
+    } catch {
+      // Non-critical — runtime already derives flags from links directly
+    }
+  };
+
   const getInteractionSourceEntityForLink = (link: InteractionLink): InteractionSourceEntity | null => {
     const sourceEntity = editorState.document.entities[link.sourceEntityId];
     return sourceEntity?.kind === "triggerVolume" || sourceEntity?.kind === "interactable" ? sourceEntity : null;