Upgrade Pinia from v2 to v3 (#596)

Migrate all 37 store definitions from the deprecated object-with-id
signature to the string-id-first signature required by Pinia 3:

  defineStore({ id: 'name', ... }) → defineStore('name', { ... })

resources/scripts/admin/stores/invoice.js

@@ -22,8 +22,7 @@ export const useInvoiceStore = (useWindow = false) => {
   const { global } = window.i18n
   const notificationStore = useNotificationStore()
 
-  return defineStoreFunc({
-    id: 'invoice',
+  return defineStoreFunc('invoice', {
     state: () => ({
       templates: [],
       invoices: [],