refactor: simplified data loading with direct fetch endpoint

vite.config.ts

@@ -9,10 +9,10 @@ export default defineConfig(({ mode }) => {
       port: 3000,
       host: '0.0.0.0',
       proxy: {
-        '/api/dropbox': {
-          target: 'https://www.dropbox.com',
+        '/api/fetch-data': {
+          target: 'https://www.dropbox.com/scl/fi/b9zxn4z5i7sxwfakk5g5y/Amazon-Sell-Out-2023-2025.csv?rlkey=uoto6v0mm99py8nszy8ldtez8&st=pzn1zkrg&dl=1',
           changeOrigin: true,
-          rewrite: (path) => path.replace(/^\/api\/dropbox/, ''),
+          rewrite: () => '',  // Replace entire path with empty string (target has full URL)
           followRedirects: true
         }
       }