fix: Change nginx port to 8087 — port 80 taken by NPM

NPM handles SSL termination and proxies to 8087.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker/docker-compose.yml

@@ -73,8 +73,7 @@ services:
     image: nginx:alpine
     container_name: corrosion-nginx
     ports:
-      - "80:80"
-      - "443:443"
+      - "8087:80"
     volumes:
       - ./nginx.conf:/etc/nginx/nginx.conf:ro
       - ../frontend/dist:/usr/share/nginx/html:ro