Fixes: 1) Replace `ElNotification` calls with `useNotification` utility across all authentication and user-related composables; 2) Add missing semicolons in multiple index exports and styled components; 3) Resolve issues with reactivity in `useStore` composable by renaming and restructuring product variables;
Extra: 1) Refactor localized strings and translations for better readability and maintenance; 2) Tweak styles including scoped styles, z-index adjustments, and SCSS mixins; 3) Remove unused components and imports to streamline storefront layout.
