Remove an image's pushed names with its build tag, and take no work under the free-space floor (issue 1834)

The registry push tags the image a second time, so removing only the build tag freed nothing.
The held image a comparison pulls goes after it is read, and a node under the floor leaves the ask
to another build node instead of taking it and failing.

internal/builder/builder.go

@@ -752,18 +752,25 @@ func keepsImageLocally(publish Publisher) bool {
 	return false
 }
 
-// releaseImage removes the local image tag a build made, with a context of its own: the build's may be cancelled. A
-// tag that was never made (the build failed before it) is no fault; one that cannot be removed is said.
-func releaseImage(ctx context.Context, run Runner, tag string, say func(step, format string, args ...any)) {
+// PushedNames is implemented by a publisher that tags the image under other names to push it: the names it leaves in the
+// machine's runtime for a repository, which go with the build's own tag (novox/hq issue 1834).
+type PushedNames interface {
+	PushedNames(repository string) []string
+}
+
+// releaseImage removes the names an image was given on the node, in one command: its layers go only with the last. It runs
+// with a context of its own, the build's may be cancelled. A name never made (the build failed before it) is no fault;
+// one that cannot be removed is said, and removal is said only when the image is gone.
+func releaseImage(ctx context.Context, run Runner, names []string, say func(step, format string, args ...any)) {
 	removing, done := context.WithTimeout(context.WithoutCancel(ctx), time.Minute)
 	defer done()
-	if _, err := run(removing, "", "docker", "rmi", tag); err != nil {
+	if _, err := run(removing, "", "docker", append([]string{"rmi"}, names...)...); err != nil {
 		if !strings.Contains(err.Error(), "No such image") {
-			say("image", "the local image %s could not be removed, and goes with the week's sweep: %v", tag, err)
+			say("image", "the local image %s could not be removed, and goes with the week's sweep: %v", strings.Join(names, ", "), err)
 		}
 		return
 	}
-	say("image", "the local image %s is removed: the registry holds it", tag)
+	say("image", "the local image %s is removed: the registry holds it", strings.Join(names, ", "))
 }
 
 // contextFrom clones an image artifact's own build context, when it names one apart from this
@@ -1246,7 +1253,11 @@ func one(ctx context.Context, run Runner, publish Publisher,
 		// a tag per module and commit left on the node was the 96 GB of a full disk. Only a node publishing nowhere (a
 		// mesh being raised) keeps it, since the local image is then the artifact.
 		if !keepsImageLocally(publish) {
-			defer releaseImage(ctx, run, local, say)
+			names := []string{local}
+			if p, ok := publish.(PushedNames); ok {
+				names = append(names, p.PushedNames(module+"/"+a.Name)...)
+			}
+			defer releaseImage(ctx, run, names, say)
 		}
 		if _, err := run(ctx, buildDir, "docker", invocation...); err != nil {
 			return catalogue.Built{}, fmt.Errorf("%s: building %s failed: %w", module, a.Name, err)