monitoring: set up container resource monitoring and alerts

[lfariabr]

Add resource (CPU, memory, disk) monitoring and alerting for all Docker containers (frontend, backend, MongoDB, nginx) to proactively detect performance, resource exhaustion, and security issues.

Tech stack:

• Docker Compose (orchestrates Next.js frontend, Node.js backend, MongoDB, nginx)
• Deployed on DigitalOcean (with available Monitoring & Alerts, plus support for Prometheus/Grafana stack)

Action Items:

• Integrate docker stats and container healthchecks for basic local resource visibility
• Set up a monitoring stack:
  • Install Prometheus and Grafana via docker-compose, or use DigitalOcean Monitoring in production
• Configure dashboards and email/Slack alerts for high CPU (>80%), memory usage, restarts, or service unavailability
• Optional: Add log forwarding to Loki, Sentry, or a cloud logging provider

Docker Compose Example:

services:
  prometheus:
    image: prom/prometheus
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
    ports:
      - "9090:9090"
  grafana:
    image: grafana/grafana
    ports:
      - "3001:3000"

Acceptance Criteria:

• Grafana dashboard shows live resource usage for each service
• Alerts trigger on high resource conditions or container restarts
• Monitoring and alert setup documented in backend/docs/ and/or frontend/docs/