Add invoice sharing via QR code modal

[Kingsman-99]

Overview

Sharing an invoice currently requires copying a URL manually. Add a QR code modal so creators can display a scannable code that opens the invoice on any device.

Acceptance Criteria

• "Share via QR" button on the invoice detail page and invoice cards
• Opens a modal containing a QR code encoding the public invoice preview URL
• QR code generated client-side using qrcode or react-qr-code (lazy loaded)
• QR size: 240 × 240 px with the StellarSplit logo centred in the quiet zone
• "Download QR" button saves the QR as a PNG named invoice-[id]-qr.png
• "Copy Link" button below the QR copies the preview URL with a success toast
• Modal accessible (focus trapped, Escape to close, aria-label on close button)
• Works for both public and unlisted invoices (uses the preview URL in both cases)

[Kureszn]

@Kureszn has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I've reviewed the issue and believe I can contribute effectively. My experience spans software development, blockchain technologies, cybersecurity and open source collaboration. I take a structured approach to contributions carefully understanding the existing codebase, identifying the root cause and delivering a thoroughly tested implementation.

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

[LawalRahman]

@LawalRahman has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi,

I’m a full-stack and blockchain developer with experience building fintech and payment-focused applications. I work across frontend, backend, APIs, and smart contract integrations with a strong focus on turning ideas into working products quickly.

For this issue, I’d focus on delivering a simple but well-structured solution that demonstrates clear Stellar utility rather than unnecessary complexity. My priority would be reliability, clean architecture, secure implementation, and an MVP that can realistically evolve beyond the hackathon.

I’m ready to begin immediately and ship iteratively with clear progress updates.

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

[drips-wave]

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

🧑‍💻 @LawalRahman: 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

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