fix: Configure Vite for nginx reverse proxy

- Add --host flag to bind to all interfaces
- Add __VITE_ADDITIONAL_SERVER_ALLOWED_HOSTS env var for external domain
- Configure allowedHosts in vite.config.ts
- Remove duplicate vite.config.js (was overriding .ts config)
- Enable IPv4 binding for nginx proxy compatibility

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

admin-ui/vite.config.ts

@@ -56,7 +56,9 @@ export default defineConfig(({ mode }) => ({
     }
   },
   server: {
+    host: '0.0.0.0',  // Bind to all interfaces for nginx proxy compatibility
     port: 3456,
+    allowedHosts: ['dss.overbits.luz.uy', 'localhost', '.localhost'],  // Allow external domain and localhost
     proxy: {
       '/api': {
         target: 'http://localhost:8002',