feat: add bounty search bar

[adz285]

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update
• 🎨 Style/UI update
• ♻️ Code refactoring
• ⚡ Performance improvement
• ✅ Test addition/update

Checklist

• Code is clean and follows the issue spec exactly
• One PR per bounty (no multiple bounties in one PR)
• Tests included for new functionality
• All existing tests pass
• No console.log or debugging code left behind
• No hardcoded secrets or API keys

Testing

• Manual testing performed
• Unit tests added/updated
• Integration tests added/updated

Test commands run:

npm run build
npm test -- BountyGrid.test.tsx

Results:

• npm run build passed.
• npm test -- BountyGrid.test.tsx passed with 2 tests.
• Full npm test currently fails due to existing missing legacy test targets/components and missing @playwright/test, unrelated to this change.

Screenshots (if applicable)

N/A

Additional Notes

Adds a debounced search input to the bounties page so users can filter loaded bounty cards by:

• title
• description
• skills/tags
• org/repo
• tier
• token
• status

The existing status and language filters are preserved.

This PR also restores the missing shared frontend helper modules used by the current bounty UI so the frontend build can complete.

Closes #823

Wallet: 3g6VXw7izS1jZehCbdMqxzqqWsRYRsFhWy3ZxExLm7PH

[adz285]

Thanks — submitted a focused implementation for #823. Local build and the focused BountyGrid test passed. Happy to adjust anything if needed.