Implement subscription export with multiple format support

[Smartdevs17]

Context

Subscription data needs export in multiple formats.

Current Limitation

No data export functionality exists.

Expected Outcome

• Multi-format export (CSV, JSON, PDF)
• Scheduled export automation
• Export analytics
• Export API

Acceptance Criteria

• CSV export with custom columns
• JSON export with schema
• PDF export with formatting
• Scheduled export automation
• Export analytics (download counts, formats)
• Export API for integration
• Export documentation

Technical Scope

• app/services/accountingExport.ts - Export service
• backend/services/billing/ - Billing domain
• src/screens/ - Export UI
• docs/ - Export documentation

[Emoji-dot]

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

I would like to work on this issue and

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

[adepoju2006]

@adepoju2006 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I would love to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @adepoju2006 to this issue.

[primexk5]

@primexk5 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Gm maintainer, please assign me to this issue,I would won't to work on it

ℹ️ Repo Maintainers: To accept this application, review their application or assign @primexk5 to this issue.

[drips-wave]

Congratulations, @primexk5! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @primexk5: 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 🌊