added prettier message for file not found error issue #855

[vishakha1411]

Motivation

Issue #855

Modifications

• Updated loadedConfig() in GenerateOptions.swift to detect file-not-found errors (NSPOSIXErrorDomain, code 2) and emit a clearer, human-readable error message: “Configuration file not found at path: {path}. Please ensure the file exists and the path is correct.”
• Applied the same error handling logic in FilterCommand.swift for consistency.

The handling explicitly checks:

• Error domain: NSPOSIXErrorDomain
• Error code: 2 (ENOENT – No such file or directory)

For all other errors, the original error message is preserved and surfaced as before.

[czechboy0]

Looks great, thank you @vishakha1411 🙏

[vishakha1411]

Fixed CI failures caused by ambiguous ValidationError references in unit tests by explicitly using ArgumentParser.ValidationError

[vishakha1411]

Addressed the earlier CI failures around error message handling, CI is now awaiting workflow approval. Thanks!