docs(frontend): Fix proxy configuration example to match actual implementation

The README proxy configuration example incorrectly used process.env instead of the env variable from loadEnv. Changes: - Update proxy target to use env.VITE_BACKEND_URL (not process.env) - Ensure documentation matches vite.config.js implementation - Maintain consistency across all Vite configuration examples Addresses CodeRabbit critical feedback on PR #1607. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>

Author: hari-kuriakose

frontend/README.md

@@ -185,7 +185,7 @@ Backend API calls are automatically proxied in development:
 server: {
  proxy: {
  '/api': {
- target: process.env.VITE_BACKEND_URL,
+ target: env.VITE_BACKEND_URL,
  changeOrigin: true,
  secure: false,
  },