Fix export to csv btn

[Sahilagarwal623]

Description

This PR ensures that the Export to CSV button is only clickable when there is at least one transaction available.
Previously, the button remained active even if no transactions existed, leading to unnecessary clicks and empty CSV downloads.

Related Issue

Fixes #176

Motivation and Context

This change improves the user experience by preventing users from exporting empty data and adds a small validation check to enhance the app’s overall usability.

Types of Changes

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Verified that the Export to CSV button is disabled when no transactions exist.
• Verified that the button becomes enabled once at least one transaction is added.
• Tested in both local and deployed environments to confirm consistent behavior.

Screenshots (if applicable):

(Add before/after screenshots if UI is affected.)

Checklist

• My code follows the code style of this project
• I have tested the feature thoroughly
• All new and existing tests passed

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[archa8]

I cannot merge this PR as you were not assigned this issue. Also, you have made a lot of unnecessary formatting changes which makes it almost impossible to see the useful changes. I won't be able to give this PR a hacktoberfest-accepted label as well due to the unnecessary changes, which might lead to your PR being marked as spammy. Thank you!