processRewardClaim grants credits on uncertain bad_seq outcome

[DeFiVC]

Problem

In src/modules/rewards/reward.service.ts lines 119-140, when a bad_seq error occurs, txHash is set to "pending_indexer_confirmation" and execution continues to the database transaction which:

1. Marks rewardClaimed: true
2. Increments the user's credits

The on-chain transaction may not have actually succeeded. handleBadSeqError explicitly documents "the tx might actually succeed on-chain" — meaning the outcome is uncertain, yet credits are granted unconditionally.

Impact

Users may receive credits when the on-chain reward transfer did not succeed — potential double-spend.

Fix

Do not grant credits until the indexer confirms the on-chain transaction succeeded.

Severity

High

[EthTobi]

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

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[davedumto]

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Hello can i work on this issue?

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[grantfox-oss]

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@davedumto's PR #181 was approved and merged by @DeFiVC.

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