cmd/app: include template name in container metadata

This helps disambiguate active mutable containers.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/app/main.go

@@ -86,9 +86,9 @@ func main() {
 				}
 
 				config := hst.Config{
-					ID: "app.hakurei.mutable",
+					ID: "app.hakurei.mutable." + args[0],
 					Container: &hst.ContainerConfig{
-						Hostname: "mutable",
+						Hostname: args[0] + "-mutable",
 						Filesystem: []hst.FilesystemConfigJSON{
 							{FilesystemConfig: &hst.FSOverlay{
 								Target: fhs.AbsRoot,