A have waiting for a yes says whether the move changes the build alone: the composer composes the build the module runs with today's settings and secrets and the agent compares it with what runs, so a release's Approve answers it and a changed setting is still asked (ADR 0601 §1)

internal/selfcompose/selfcompose.go

@@ -1635,3 +1635,48 @@ func Transient(err error) bool {
 	}
 	return false
 }
+
+// ComposedToday is the digest of module composed at the build fp with today's settings and secrets, as this node would
+// compose it now beside its other modules at their wanted builds, the boxes it runs kept as compose keeps them, and whether
+// it composed (novox/hq ADR 0601 §1): the node agent compares it with what runs, to say whether a move to another build
+// changes the build alone. A module held, a node refused, or no placement: false, and the move is asked of a person.
+func (c *Composer) ComposedToday(ctx context.Context, module, fp string) (string, bool) {
+	c.mu.Lock()
+	fps, kept := map[string]string{}, map[string]string{}
+	for m, w := range c.wants {
+		if m == agent.NodeModule {
+			continue
+		}
+		fps[m] = w.FP
+		if mm, ok := c.modules[m]; ok && mm.FP2 != w.FP {
+			kept[m] = w.FP
+		}
+	}
+	fps[module] = fp
+	delete(kept, module)
+	if mm, ok := c.modules[module]; !ok || mm.FP2 != fp {
+		kept[module] = fp
+	}
+	own, placed := c.placements[c.env.Node]
+	inOwn := c.inOwnOf(own)
+	c.mu.Unlock()
+	if !placed {
+		return "", false
+	}
+	var running []delivery.Composed
+	if c.env.Running != nil {
+		running = c.env.Running()
+	}
+	scope := frombus.Scope{Node: c.env.Node, KeptAt: kept, InOwn: inOwn, Running: running}
+	comps, _, held, err := frombus.Compose(ctx, reader{c: c}, c.env.Mesh, scope, fps)
+	if err != nil || held[module] != "" {
+		return "", false
+	}
+	for _, comp := range comps {
+		if comp.Module == module && comp.FP == fp {
+			dig, err := delivery.ComposedDigestOf(c.keepRunning(comp, running))
+			return dig, err == nil
+		}
+	}
+	return "", false
+}