Backend: Implement Delist Orchestrator with adapter pattern

[shivi14112007-create]

Summary

Implement a centralized delist orchestrator using an adapter pattern to coordinate delisting across multiple marketplaces.

Tasks

• Design marketplace adapter interface
• Implement orchestrator service
• Integrate existing marketplace adapters
• Handle retries and failures
• Add logging and error handling
• Add backend tests

Acceptance Criteria

• Delist operation works across supported marketplaces
• Failed operations are reported correctly
• Adapter pattern is extensible for future marketplaces

Related to #150

[shivi14112007-create]

hey @rushikesh-bobade , can you assign me this issue now.

[github-actions]

Hi @shivi14112007-create! 👋

Thank you for your interest in contributing to this repository! Please wait until a maintainer officially assigns you to this issue before opening a Pull Request.

While you wait, please consider starring ⭐ this repository to show your support! We review requests regularly and will assign it as soon as possible if it's available. Happy coding! 🚀