fix: update all port 80 references to 8080 after nginx-unprivileged switch

[coderabbitai]

Summary

The Dockerfile was updated in PR #61 to use nginxinc/nginx-unprivileged:alpine and expose port 8080 instead of 80, but several related files still reference the old port 80 and need to be updated for consistency.

Files to update

• docker/nginx.conf: Change the server listen directive from listen 80 to listen 8080
• docker/docker-compose.yml: Update the service port mapping from 7777:80 to 7777:8080, change NGINX_PORT env value from 80 to 8080, and update Traefik label loadbalancer.server.port from 80 to 8080
• docker/README.md: Update documented Traefik label examples (loadbalancer.server.port=80) to 8080
• .github/workflows/release.yml: Replace docker run -p 7777:80 with docker run -p 7777:8080

Context

Flagged during code review of PR #61: #61 (comment)

Reported by: @Delgado74