Add a distinct error state to ExportButton instead of mislabeling failures as complete

[RUKAYAT-CODER]

Overview
src/components/ExportButton.tsx (lines 70-76) surfaces failures only by reusing the 'completed' progress stage at 100%, mislabeling a failed export as complete, and the component has no distinct error styling or disabled/empty guard for missing template data. Add an explicit error state and guard against empty template data.

[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

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

[Ghadaffijr]

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

I would love to take this on and can have the pr ready before the deadline.

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

[Olamidepy]

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

Hi Maintainer,

I would love to be assigned to this issue.

I’m a Full-Stack Developer and I also actively explore blockchain development and smart contracts, which has strengthened my problem-solving skills and attention to code quality.

After reviewing the issue, I believe I can contribute effectively and deliver a well-tested solution within the expected standards of the project.

ETA: 6 hours

Thank you for your consideration.

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

[drips-wave]

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

🧑‍💻 @Olamidepy: 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 🌊

[heyrapto]

Hello maintainer, I'd love to work on this issue.