Add Next.js build cache to deployment workflow for improved performance. Update all workflows to use `pnpm install --frozen-lockfile --prefer-offline` for faster and more reliable dependency management.
Refactor GitHub Actions workflows to introduce matrix builds for `backend`, `frontend`, and `documentation` components. Upgrade actions versions, add pull request triggers, and improve caching with pnpm store integration. Adjust Node.js version to 20 and enforce `--frozen-lockfile` for dependency installation.
Introduce `deploy.yml` to automate deployment to production on `prod` branch push. Includes setup for Node.js, pnpm caching, linting, building, and Docker Compose deployment. Update `docker-compose.prod.yml` to use environment variables for enhanced configurability.
