Fix reference error when opening cluster view (#3824)

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/renderer/api/catalog-entity-registry.ts

@@ -31,7 +31,7 @@ import { once } from "lodash";
 export type EntityFilter = (entity: CatalogEntity) => any;
 
 export class CatalogEntityRegistry {
-  @observable.ref activeEntity: CatalogEntity;
+  @observable protected activeEntityId: string | undefined = undefined;
   protected _entities = observable.map<string, CatalogEntity>([], { deep: true });
   protected filters = observable.set<EntityFilter>([], {
     deep: false,
@@ -46,6 +46,22 @@ export class CatalogEntityRegistry {
     makeObservable(this);
   }
 
+  get activeEntity(): CatalogEntity | null {
+    return this._entities.get(this.activeEntityId) || null;
+  }
+
+  set activeEntity(raw: CatalogEntity | string | null) {
+    if (raw) {
+      const id = typeof raw === "string"
+        ? raw
+        : raw.getId();
+
+      this.activeEntityId = id;
+    } else {
+      this.activeEntityId = undefined;
+    }
+  }
+
   init() {
     ipcRendererOn("catalog:items", (event, items: (CatalogEntityData & CatalogEntityKindData)[]) => {
       this.updateItems(items);