Fix Vite build configuration for CI

- Set root to 'client' directory to find index.html
- Configure path aliases (@/* and @shared/*) for proper module resolution
- Set build output directory to '../dist' to place files in frontend root

Resolves CI build failure: 'Could not resolve entry module index.html'

vite.config.ts

@@ -1,7 +1,18 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
+import path from 'path'
 
 // https://vitejs.dev/config/
 export default defineConfig({
   plugins: [react()],
+  root: 'client',
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './client/src'),
+      '@shared': path.resolve(__dirname, './shared')
+    }
+  },
+  build: {
+    outDir: '../dist'
+  }
 })