Backend: Implement indexer handler for delivery_status_updated on-chain event

[Tybravo]

📁 Implementation Directory

backend/src/indexer/deliveryHandlers.ts

🎯 Goal

Reflect smart contract status changes in the backend.

📋 Requirements

• Parse the delivery_status_updated event.\n- Update corresponding Delivery document.\n- Trigger any related WebSocket notifications.

🔧 Technical Scope

• Node.js / Express
• TypeScript
• MongoDB / Mongoose
• Stellar Soroban RPC

🌿 Branch

git checkout -b feat/indexer-delivery-status

✅ Acceptance Criteria

• Using an AI Agent to submit a PR is DISALLOWED.
• Strict Layered Architecture (Non-Negotiable): Implement using the Controller -> Service -> Model pattern.
• Data Source: Response data must be retrieved from the database. No Inline Mock Objects or Hardcoded Values usage for integration.
• Environment: Contributors must use the requested .env credentials to enable implementation with real-life data.
• API Versioning: API Must Be Versioned (e.g., /api/v1/...).
• Production Ready: Code must look production-ready (robust error handling, strong typings).
• Proof of Work: Upload a screenshot of work done (i.e., API Response Success via Postman/Browser, or all unit tests passed successfully).
• PR Content: Must include Closes #[issue_id] with a work done summary.

📌 PR Requirements

• ⚠️ Assignment required before starting — comment on this issue to request assignment.
• PR must comply fully with the CONTRIBUTING.md.
• AI Agent submissions are DISALLOWED and will be closed without review.
• No Inline Mock Objects or Hardcoded Values usage for integration.

[aburex12345]

@aburex12345 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi maintainer, I'd like to work on this issue.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @aburex12345 to this issue.

[spiffamani]

@spiffamani has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I'm a full-stack Software Engineer
I'd love to take this on — thanks for considering me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @spiffamani to this issue.

[drips-wave]

Congratulations, @spiffamani! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @spiffamani: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

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