Add integration test for wallet holdings endpoint returning correct key balances

[Chucks1093]

Summary

The wallet holdings endpoint needs integration test coverage confirming the response contains accurate key balances from the ownership read model.

Scope

• Seed the ownership read model with two creators and different balances for a test wallet
• Call GET /wallets/:address/holdings and assert the response contains both entries with correct balances
• Assert zero-balance entries are excluded

Acceptance Criteria

• Test passes with correct balances for each held creator
• Zero-balance creator is not included in the response

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Coordinate on Telegram

[N-thnI]

Dear maintainer
Please assign me this issue

[ekwe7]

I would love to work on this issue. I have experience building production ready applications and collaborating through GitHub workflows. I'll carefully analyze the current implementation, propose a reliable solution, and submit a well-tested PR. My focus is on clean code, maintainability, and timely delivery

[Topmatrixmor2014]

Hi maintainer, I would love to work on this issue. I have studied the details of the issue description and I understood the requirements. I shall deliver with qualitative feedback and promptly

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[grantfox-oss]

🦊 GrantFox — @Topmatrixmor2014 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #429)
2. Your PR will be reviewed by the accesslayerorg maintainers

Good luck! Track your progress on GrantFox.