feat(docker): add httpx security tool and health check

[KirobotDev]

Changes

Added

• Security tool: Added httpx (v1.6.0) from ProjectDiscovery to the Docker image
  • Builder stage: Install via go install
  • Runtime stage: Copy binary to /usr/local/bin/
• Health check: Added Docker HEALTHCHECK instruction
  • Interval: 30s
  • Timeout: 10s
  • Start period: 5s
  • Retries: 3

Why

• httpx provides fast HTTP probing and technology detection, complementing existing recon tools (subfinder, WhatWeb, nmap)
• Health check enables better container orchestration monitoring (Kubernetes/Docker Swarm)

Testing

• Build image: docker build -t shannon:test .
• Verify httpx: docker run --rm shannon:test httpx -version
• Check health endpoint responds on :3000/health