[Proposal] Add Production Multi-Stage Dockerfile and Docker Compose Workflow

[NumanKhan0103]

Hi maintainers,

I noticed that the project currently relies on manual host setups.

To improve onboarding for new developers and simplify production deployments, I would like to contribute the following:

1. Multi-Stage Dockerfile: Lean, security-hardened (non-root execution), and optimized with layer caching.
2. Docker Compose Workflow: Fully containerized environment for running the web app, backend, and database dependencies seamlessly.
3. CI Pipeline Integration: GitHub Action workflow to test container builds on PRs.

Would you be open to accepting a pull request for this?