feat: add initial styling and layout for portal views

- Created a global CSS file for consistent styling across the application.
- Implemented the Explore, Home, Topics, and various user views with responsive design.
- Added a Login view with OTP functionality and a Checkout view for order processing.
- Developed a NotFound view for handling 404 errors.
- Established a configuration file for Vite with Tailwind CSS integration.

frontend/portal/vite.config.js

@@ -0,0 +1,22 @@
+import tailwindcss from '@tailwindcss/vite'
+import vue from '@vitejs/plugin-vue'
+import { defineConfig } from 'vite'
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  plugins: [
+    vue(),
+    tailwindcss(),
+  ],
+  server: {
+    host: '0.0.0.0',
+    port: 5174,
+    strictPort: true,
+    proxy: {
+      '/v1': {
+        target: 'http://localhost:8080',
+        changeOrigin: true
+      }
+    }
+  },
+})