Add test confirming fee exemption list takes precedence over per-token fee tiers

[Chuks-coderr]

Overview

When a sender is on the fee exemption list and the token also has a per-token fee tier, the exemption must take precedence and no fee should be charged.

Proposed Solution

• Configure a per-token fee tier for token T, add sender S to the exemption list, create a stream from S using token T
• Assert zero protocol fee deducted

Acceptance Criteria

• Exempt sender pays zero fee even when the token has a configured tier
• Non-exempt sender using the same token pays the per-token fee
• Test covers both scenarios for contrast

[jojoafrica1]

@jojoafrica1 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello maintainer I would like to work on the project

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[drips-wave]

Congratulations, @jojoafrica1! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

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