[CourseRegistry] Trigger payout on course completion

[Kaylahray]

Description

A cross-contract call from the CourseRegistry to the RewardPool. When a learner marks their final module as complete, the contract calls distribute_reward on the RewardPool so learners are instantly compensated without manual intervention.

User Story

As the Learnault Protocol,
I want to automatically trigger a USDC reward when a learner finishes a course,
so that learners are instantly compensated for their educational progress without manual intervention.

Requirements and Context

• Files: contracts/course-registry/src/lib.rs, contracts/course-registry/src/test.rs
• After incrementing a learner's progress, check if progress == total_modules
• If true, initialize RewardPoolClient and call distribute_reward with the predefined course payout amount

Suggested Implementation

// IN FUNCTION: complete_module(env: Env, learner: Address, course_id: u32)
// 1. // ... progress increment logic ...
// 2. if new_progress == course.total_modules {
// 3.     let reward_pool = RewardPoolClient::new(&env, &reward_pool_address);
// 4.     let base_reward = 10_0000000; // e.g., 10 USDC
// 5.     reward_pool.distribute_reward(&env.current_contract_address(), &learner, &base_reward);
// 6.     emit CourseCompleted event.
// 7. }

Acceptance Criteria

• USDC is transferred to the learner upon finishing the last module.
• Fails if the CourseRegistry is not whitelisted in the RewardPool.

Submission Guidelines

• Branch: feat/course-completion-payout
• Depends on: RewardPool distribute_reward function
• PR: feat(course-registry): trigger USDC payout on course completion

[onajidavid87-web]

@onajidavid87-web has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Please I’d like to work on this issue as this issue is within my expertise

ℹ️ Repo Maintainers: To accept this application, review their application or assign @onajidavid87-web to this issue.

[ayomidearegbeshola29-dev]

@ayomidearegbeshola29-dev has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I will love to work on this pls

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ayomidearegbeshola29-dev to this issue.

[drips-wave]

Congratulations, @onajidavid87-web! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @onajidavid87-web: 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

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊