[DevOps] Containerize backend with Docker & Compose

[Richardkingz2019]

Closes #10
n## Summary

Adds production-grade containerization for the EquipChain backend using a Docker multi-stage build and a Docker Compose stack (API + Redis) for local development and reproducible deployments.\n\n

What changed\

Docker multi-stage build:
Builder stage installs full dependencies and runs the test suite (npm test) during image build.\n - Production stage installs only production dependencies (npm ci --omit=dev), sets NODE_ENV=production, and runs as the non-root node user

. Docker Compose stack:\n - api service built from the production target, published on port 3000, and configured via environment variables (supports overriding via a local .env file).\n - redis service using redis:7-alpine with a persistent named volume.

Healthchecks for both api (/api/health) and redis (redis-cli ping) plus an isolated named bridge network.

Development override:\n - docker-compose.override.yml enables bind-mounting the working tree and uses node --watch for a simple edit/restart loop without extra dependencies.

Build context cleanup:\n - .dockerignore excludes node_modules, git metadata, env files, and other non-essential paths to keep Docker builds fast and deterministic.\n- Documentation:

README updated with Docker/Compose usage and helper scripts.\n\n## How to run

Build and run the production image:\n - docker build -t equipchain-backend:local .

• docker run --rm -p 3000:3000 --env-file .env equipchain-backend:local\n- Run API + Redis via Compose:\n - docker compose up --build

-n## Local verification\n- npm ci\n- npm test\n- npx eslint .

closes #10

[KarenZita01]

Failed CI. Try an fix it