Add Shopify Integration Training module to SDE programfeat: Add Shopify Integration Training module to SDE program

[vaibhaviupreti-hotwax]

Description

This PR introduces a comprehensive new training module on Shopify Integration to the existing SDE curriculum.

Key Changes:

• Added Course Plan: Created shopify-integration-course-plan.md detailing architectural concepts, authentication mechanisms (OAuth/JWT), API strategies (REST vs GraphQL), execution, and operational workflows.
• Updated Curriculum: Integrated the new Shopify module into the main sde-program.md as Module 9.
• Reordered Content: Shifted and renumbered subsequent modules (e.g., Detailed Design, Experience Applications) to maintain a seamless, logical flow in the program.

Purpose

To provide trainees with a structured, step-by-step roadmap for learning and executing robust Shopify integrations, ensuring they understand best practices, security, and multi-brand architecture.

Files Changed

• sde-program.md (Modified)
• shopify-dev/shopify-integration-course-plan.md (New)