git push --set-upstream origin docs/add-ci-cd-diagram-and-deployment-guide

[coolert]

PR Summary

This PR improves the engineering documentation by updating the CI/CD section in the README and introducing a dedicated Deployment Guide.

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Changes

README

• Added CI/CD Pipeline Diagram under the CI/CD section
• Added a concise Deployment (Overview) section following CI/CD for better structure and clarity

Documentation

• Added new file: docs/deployment.md
• Includes a clean, production-ready deployment flow description
• Documents GitHub Actions deploy workflow, server-side deploy script, Supervisor worker, Cron scheduling, and permissions

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Type of Change

• Feature
• Fix
• Docs
• Refactor
• CI
• Other