Add integration test for webhook delivery retrying after a 500 response from callback URL

[Chucks1093]

Summary

When a webhook callback URL returns a 500 error, the server should retry the delivery rather than treating it as a permanent failure. An integration test should confirm the retry fires and uses the correct backoff before the next attempt.

Scope

• Register a webhook with a mock callback URL that returns 500 on the first call and 200 on the second
• Simulate a trade event
• Assert the callback was called twice
• Assert the second call happened after the backoff delay
• Assert the webhook is not marked as failed after a successful retry

Acceptance Criteria

• Callback called twice: once failing, once succeeding
• Webhook not marked as failed after successful retry
• Retry fires after the configured backoff delay

ETA: 12 hours

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Coordinate on Telegram

[Naajih09]

Hi, I'd like to work on this issue. I've gone through the description and acceptance criteria and I'm confident I can deliver it. I'll make sure every acceptance criterion is met and submit a clean, tested PR. Please assign it to me.

[Martins-594]

Hi, I'd like to work on this issue. I've gone through the description and acceptance criteria and I'm confident I can deliver it. I'll make sure every acceptance criterion is met and submit a clean, tested PR. Please assign it to me.

[Hollujay]

Hi @Chucks1093, I would like to work on this issue because I will get it done.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@Hollujay's PR #581 was approved and merged by @Chucks1093.

🏆 @Hollujay: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (48 total points). Track your full progress on GrantFox.

👏 Great work, @Hollujay! Keep contributing to accesslayerorg.