node-engine.composition shows the node's own fields and what the last pass held (issue 774)

Reading ace's node composition gave four resources twice and no way to see that one revision named no provisioner
client's account. The verb now shows, for module node, the revision's provisioner account beside what runs names, its
adoption, how many identities, groups and libraries it names, and each module the composer's last pass held with why.

Claude-Session: https://claude.ai/code/session_01JG73KG7AfSdh6FP8VrBqCn

internal/selfcompose/selfcompose.go

@@ -218,6 +218,13 @@ type Pass struct {
 	Earlier bool `json:"earlier,omitempty"`
 }
 
+// LastHeld is what the last pass held, each module with why; nil before a pass or when it held none.
+func (c *Composer) LastHeld() map[string]string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return maps.Clone(c.last.Held)
+}
+
 // askedWithin is how recent a pass answers an ask of the verb compose without a new one: the first wait after a seat
 // that did not answer (laterAgain's first).
 var askedWithin = 5 * time.Second