Refactor frontend structure and update dependencies

- Changed the main entry point from main.jsx to main.tsx for TypeScript support.
- Removed Tabler JS import and integrated Tailwind CSS for styling.
- Updated package.json and package-lock.json to include new dependencies such as @fontsource-variable/geist and tailwindcss, while removing unused ones.
- Enhanced Vite configuration with path aliasing for improved import management.
- Deleted unused App.css and App.jsx files to streamline the project structure.

Made-with: Cursor

frontend/src/CommunitiesManager.jsx

@@ -18,7 +18,7 @@ import {
   IconDownload,
   IconDeviceFloppy,
   IconPlugConnected
-} from '@tabler/icons-react';
+} from '@/lib/icons';
 import PageHeader from './components/PageHeader.jsx';
 import PortalDropdown from './components/PortalDropdown.jsx';
 import EmptyState from './components/EmptyState.jsx';
@@ -27,7 +27,7 @@ import SavedFilters from './components/SavedFilters.jsx';
 import FormModal from './components/FormModal.jsx';
 import ConfirmModal from './components/ConfirmModal.jsx';
 import FormField from './components/FormField.jsx';
-import ErrorAlert from './components/ErrorAlert.jsx';
+import { ErrorAlert } from '@/components/shared/feedback';
 import Pagination from './components/Pagination.jsx';
 import IconPicker from './components/IconPicker.jsx';
 import { getIconById } from './lib/brandIcons.js';