- [ ] Add loading state guard to `startNewSession` and `completeTransaction` actions in `resources/js/stores/pos.js` to prevent race conditions.
- [ ] Update the "Confirm & Pay" button in `resources/js/Pages/PosMain.vue` to be disabled when `posStore.loading` is true and add a loading spinner.
- [ ] Modify the `getPosSessions` method in `app/Http/Controllers/Market/PosController.php` to exclude sessions with status `active` from the history records.
- [ ] Test the checkout flow to ensure that double-clicking the completion button does not trigger multiple new session initializations.
- [ ] Verify that the "empty transaction" is no longer visible in the POS History table upon completion of a sale.