feat: add UI components and improve layout

- Introduced new UI components: Input, Label, ScrollArea, Separator, Sheet, Skeleton, Table.
- Implemented utility function for class name merging.
- Enhanced the authenticated layout with a sidebar and user menu.
- Added login functionality with improved UI and error handling.
- Integrated theme provider for consistent theming across the application.
- Updated styles with Tailwind CSS and custom properties for dark mode support.
- Refactored routes to utilize new components and improve user experience.

vite.config.ts

@@ -2,10 +2,11 @@ import { defineConfig } from 'vite'
 import viteReact from '@vitejs/plugin-react'
 import tanstackRouter from '@tanstack/router-plugin/vite'
 import { resolve } from 'node:path'
+import tailwindcss from '@tailwindcss/vite'
 
 // https://vitejs.dev/config/
 export default defineConfig({
-  plugins: [tanstackRouter({ autoCodeSplitting: true }), viteReact()],
+  plugins: [tanstackRouter({ autoCodeSplitting: true }), viteReact(), tailwindcss()],
   resolve: {
     alias: {
       '@': resolve(__dirname, './src'),