1d81db3af5
- Remove all unwrap() calls from SftpAttrs::serialize() and from_metadata() - Add extension advertisement in SSH_FXP_VERSION (10 extensions declared) - Map std::io::ErrorKind to proper SSH_FX_* status codes (NotFound→FX_NO_SUCH_FILE etc.) - Add restrict_absolute flag for chroot-like path confinement mode - Add MAX_HANDLES limit (4096) to prevent handle exhaustion - Add MAX_XFER_SIZE (1MB) and MAX_HASH_SIZE (256MB) OOM protection - Fix test compilation errors (SftpHandler::new signature) - Add build_status_from_io_error() helper for consistent error mapping