fix(footer): handle null/undefined version data gracefully

[Ishitadubeyy]

This PR improves the footer by handling missing or unavailable version metadata more gracefully.

Previously, when the backend version information was not available or not configured, the footer could display null or undefined values directly in the UI. This created a poor user experience, especially for contributors or users running the frontend without a fully configured backend environment.

This change ensures that the footer now shows a clean fallback message instead of rendering incomplete metadata.

Changes
Updated the footer rendering logic to safely handle missing version information
Prevented null and undefined values from appearing in the UI
Added a fallback message when version metadata is unavailable
How to test
Run the application without backend version information available
Open the UI and check the footer section
Confirm that it no longer displays null or undefined
Verify that a clean fallback message such as "Version information unavailable" is shown instead
If backend version data is available, confirm that the footer still renders version details correctly

Closes #243

[github-actions]

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