virtual sample : create virtual sample store, activate dl image btn

src/stores/virtualSample.js

@@ -0,0 +1,11 @@
+import { defineStore } from "pinia";
+import { ref, watch } from "vue";
+
+export const useVirtualSampleStore = defineStore("virtual-sample", () => {
+  const activeTab = ref("dynamic");
+  const currentFile = ref(null);
+
+  watch(activeTab, () => (currentFile.value = null));
+
+  return { activeTab, currentFile };
+});