Fix CI/CD for backend

[Jenish-1235]

This pull request introduces several improvements to the deployment and configuration of the backend service, focusing on secure handling of credentials, enhanced verification of Docker images in CI, and production readiness for Docker Compose. The main themes are improved secret handling, more robust CI image verification, and the addition of a production Docker Compose file.

CI/CD and Deployment Improvements

• Enhanced the CI image verification step to use docker-compose, spinning up dependent services (postgres, redis, and backend) with health checks and environment variables sourced from GitHub secrets. This ensures the pushed image is tested in a realistic environment before deployment. (.github/workflows/ci.yml)
• Added a new docker-compose.prod.yml for production deployments, defining services for postgres, redis, and the backend, with secure environment variable handling, health checks, and persistent volumes. (docker-compose.prod.yml)

Configuration and Security Enhancements

• Updated the config.py to URL-encode the postgres and redis passwords (and user for postgres) when constructing connection URLs, preventing issues with special characters in credentials. (config.py) [1] [2] [3]

Minor Workflow Changes

• Removed emoji from build status in workflow summary for a cleaner output. (.github/workflows/ci.yml)