Summary

Make fd_fdstat_get and fd_filestat_get return richer Preview1-compatible rights and metadata instead of the current minimal subset.

Parent tracking issue: #15
Suggested implementation order: 7 / 39

References

• https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1555
• https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1630

Acceptance criteria

• Returned fd/file metadata more closely matches Preview1 expectations for files, directories, and stdio.
• Regression tests cover representative descriptor/file cases.