Convert all store files from JavaScript to TypeScript

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

src/stores/modal.ts

@@ -0,0 +1,18 @@
+import { defineStore } from 'pinia';
+import { MODAL_ACCT_INFO, } from '@/constants/constants.js';
+
+export const useModalStore = defineStore('modalStore', {
+  state: () => ({
+    isModalOpen: false,
+    whichModal: MODAL_ACCT_INFO,
+  }),
+  actions: {
+    openModal(whichModal) {
+      this.isModalOpen = true;
+      this.whichModal = whichModal;
+    },
+    async closeModal(){
+      this.isModalOpen = false;
+    },
+  },
+});