fix(production): Configure frontend build for api.smoothschedule.com subdomain

- Update nginx build context to ../smoothschedule-frontend (matches deployment structure)
- Add VITE_API_URL build arg to pass API URL during frontend build
- Fixes login issues caused by incorrect API endpoint configuration

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

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

smoothschedule/docker-compose.production.yml

@@ -48,8 +48,10 @@ services:
 
   nginx:
     build:
-      context: ../frontend
+      context: ../smoothschedule-frontend
       dockerfile: Dockerfile.prod
+      args:
+        VITE_API_URL: https://api.smoothschedule.com
     depends_on:
       - django
     ports: