Expand Error Variant in wit/handlers.wit

[coderabbitai]

During the review of PR #202, it was identified that the error variant in wit/handlers.wit could benefit from being expanded to include more specific error types. This enhancement aims to improve error handling by allowing developers to handle different error conditions more precisely.

A TODO comment in the file suggests the need for this improvement. Addressing this will make the error handling mechanism more developer-friendly and precise.

For more context, see the PR discussion: #202 and the specific comment: #202 (comment)

@sporkmonger, this issue has been opened to track the enhancement for future consideration, ensuring it's not overlooked in subsequent development efforts.