No CI/CD for testing — only draft-pdf.yml workflow exists

[GaneshPatil7517]

• No unit tests, no linting, no build checks anywhere
• Propose adding GitHub Actions for: pytest, flake8/ruff, Dockerfile build validation

[GaneshPatil7517]

Hello @pradeeban ,
When convenient, could you please review this pull request?
I’d appreciate your feedback. Thank you. #233