Implement subscription group billing with member management

[Smartdevs17]

Context

Group subscriptions need billing management.

Current Limitation

No group billing exists.

Expected Outcome

• Group billing management
• Member billing allocation
• Group analytics
• Group admin tools

Acceptance Criteria

• Group billing management
• Member billing allocation
• Group analytics
• Group admin tools
• Group invitations
• Group API
• Group documentation

[BigMick03]

@BigMick03 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Please assign to me. I will fix immediately

ℹ️ Repo Maintainers: To accept this application, review their application or assign @BigMick03 to this issue.

[susanyusuf]

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

Hi maintainer i will love to work on this project please.

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

[drips-wave]

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

🧑‍💻 @susanyusuf: 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.

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