improve voting contract error handling

[Gozirimdev]

Close #509

name: Pull Request
about: Submit changes to Soroban Playground
title: ''
labels: ''
assignees: ''

What does this PR do?

Related Issue

Closes #

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / Code improvement
• Other (please describe):

🗂️ Affected Area(s)

• frontend/ — Next.js UI / Monaco editor
• backend/ — Express API routes (/compile, /deploy, /invoke)
• contracts/ — Example Soroban contracts
• .github/ — Templates, workflows, CI
• Documentation / README
• Other:

How Has This Been Tested?

• Tested in the browser (local dev server)
• Verified changes work across different missions
• Checked Monaco Editor behavior (if applicable)
• Ran all existing tests (npm test)
• No new console errors or warnings

Screenshots / Demo (if applicable)

Before

After

Checklist

• I have performed a self-review of my code
• I have commented my code where necessary
• I have updated the documentation (if needed)
• My changes do not introduce new warnings or errors
• New and existing tests pass locally

Related Issues or References

Additional Context

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[ayomideadeniran]

Pr under review