feat(backend): Add transaction receipt normalization with stable schema

[Viky207]

Problem

Receipts service has TODO; not normalized or stored.

Task

Implement receipt normalization and persistence.

Acceptance Criteria

• ReceiptNormalizer produces stable schema
• Stored in Supabase with txHash unique
• GET /v1/receipts/tx/:txHash
• GET /v1/receipts/address/:address
• Includes status, amounts, fees, timestamps
• Backfill from Horizon on first access

[Achievers-sketch]

@Achievers-sketch has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I can implement stable receipt normalization and Supabase persistence, enforce unique transaction hashes, add both query endpoints, and backfill missing receipts from Horizon.

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

[kceeglo345-dev]

@kceeglo345-dev has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I would love to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @kceeglo345-dev to this issue.

[drips-wave]

Congratulations, @kceeglo345-dev! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @kceeglo345-dev: 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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