fix: add missing snapshot methods to containerd driver

Author: alexisbouchez

runtime/drivers/containerd/task.go

@@ -49,6 +49,24 @@ func (ct *containerTask) Start(ctx context.Context) error {
 	return fmt.Errorf("containerd driver start not fully implemented - needs OCI runtime integration")
 }
 
+// StartFromSnapshot starts the container by restoring from a snapshot.
+// Note: Containerd containers don't support VM-style snapshots.
+func (ct *containerTask) StartFromSnapshot(ctx context.Context, globalSnapshotPath, jailSnapshotPath string) error {
+	return fmt.Errorf("containerd driver does not support snapshot restore")
+}
+
+// Snapshot saves the container state to a file.
+// Note: Containerd containers don't support VM-style snapshots.
+func (ct *containerTask) Snapshot(ctx context.Context, path string) error {
+	return fmt.Errorf("containerd driver does not support snapshots")
+}
+
+// Restore restores the container state from a snapshot file.
+// Note: Containerd containers don't support VM-style snapshots.
+func (ct *containerTask) Restore(ctx context.Context, path string) error {
+	return fmt.Errorf("containerd driver does not support snapshot restore")
+}
+
 // monitor watches the task and handles exit.
 func (ct *containerTask) monitor() {
 	defer close(ct.waitChan)