feat: Implement deletable event sphere management and refactor point instances for better event handling

app/src/store/simulation/useSimulationStore.ts

@@ -24,6 +24,28 @@ export const useSelectedEventSphere = create<SelectedEventSphereState>()(
     }))
 );
 
+interface DeletableEventSphereState {
+    deletableEventSphere: THREE.Mesh | null;
+    setDeletableEventSphere: (mesh: THREE.Mesh | null) => void;
+    clearDeletableEventSphere: () => void;
+}
+
+export const useDeletableEventSphere = create<DeletableEventSphereState>()(
+    immer((set) => ({
+        deletableEventSphere: null,
+        setDeletableEventSphere: (mesh) => {
+            set((state) => {
+                state.deletableEventSphere = mesh;
+            });
+        },
+        clearDeletableEventSphere: () => {
+            set((state) => {
+                state.deletableEventSphere = null;
+            });
+        },
+    }))
+);
+
 interface SelectedEventDataState {
     selectedEventData: { data: EventsSchema; selectedPoint: string } | undefined;
     setSelectedEventData: (data: EventsSchema, selectedPoint: string) => void;