`add` operation not storing the name of the file correctly.

[S4tvara]

Describe the bug

After performing the add operation, the file name is not saved correctly. The program takes the last segment of the file path and uses it as the file name instead of preserving the original file name.

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To Reproduce

Steps to reproduce the issue:

1. Create a vault.
2. Add test files from different directory paths.
3. Run the ls command.
4. Observe that files appear with incorrect names.

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Expected behavior

Files should be saved with their correct original names, regardless of their directory paths.

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Screenshots

If applicable, add screenshots to help explain the issue.

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Additional context

The issue occurs during the add operation — the file name handling logic seems to extract only the last path segment instead of the intended file name.

[GauravJangra9988]

@SubstantialCattle5 hey, I would like to work on this, please assign me.