client: Make ImageFileRequest require a ReadWriteSeeker

This is a small Go API break which is needed to address a security issue
where we need the ability to re-hash the final image files.

This is part of a fix for CVE-2026-33542.

Reported-by: wl2018
Signed-off-by: Stéphane Graber <stgraber@stgraber.org>

Author: stgraber

client/interfaces.go

@@ -502,10 +502,10 @@ type ImageCreateArgs struct {
 // The ImageFileRequest struct is used for an image download request.
 type ImageFileRequest struct {
 	// Writer for the metadata file
-	MetaFile io.WriteSeeker
+	MetaFile io.ReadWriteSeeker
 
 	// Writer for the rootfs file
-	RootfsFile io.WriteSeeker
+	RootfsFile io.ReadWriteSeeker
 
 	// Progress handler (called whenever some progress is made)
 	ProgressHandler func(progress ioprogress.ProgressData)