hotfix: Restrict Failure to non-success statuses only

[IMustafaZeynali]

Summary

Result.Failure(ResultStatus resultStatus, string? errorMessage = null) currently accepts any ResultStatus, including success statuses (Success, Created, NoContent). That contradicts the method name and intent.

Why

Callers can accidentally create a "failure" result that reports success (IsSuccess == true), which is confusing and error-prone.

Proposed change

• Validate that resultStatus is a non-success status before creating the result
• Throw a clear exception (or otherwise reject) when a success status is passed
• Add/update unit tests for valid and invalid inputs

Context

Feedback from community code review.

Reported by
Thanks to Omid Rezaei Nejad for reporting this.