Convert all store files from JavaScript to TypeScript

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/stores/loading.ts

@@ -0,0 +1,12 @@
+import { defineStore } from "pinia";
+
+export const useLoadingStore = defineStore('loadingStore', {
+  state: () => ({
+    isLoading: true,
+  }),
+  actions: {
+    setIsLoading(isLoadingBoolean) {
+      this.isLoading = isLoadingBoolean;
+    }
+  },
+});