Judge a machine root-free only on a positive, fresh measure, and believe a verified sender only there (hq ADR 0259 §8, review H2/H3)

The agent-root probe read the sudo module's answer, given in the machine's runtime as the very account
an agent could become, and took a missing account, a missing answer or no accounts as a pass. One
judgement now decides: the machine names an agent account its node-engine judged unable to become
root within 15 minutes (agentConfined, mesh-controller #164), and the login shell's execute is not
served there; anything not read is not free. The probe raises agent-root on it, the new root-free
verb answers it live for the router, and a push composes verified-sender for a kind only while its
machine and the router's pass it.

internal/broker/users.go

@@ -70,6 +70,10 @@ type Records struct {
 	// Interchangeable is each module whose definition says its instances are the same anywhere
 	// (ADR 0160), which decides whether the module's plain subject is issued to every instance.
 	Interchangeable map[string]bool
+	// RootFree is each machine judged root-free when this was composed (novox/hq ADR 0259 §8): it names an
+	// account agents run as, judged unable to become root by its node-engine, and serves no login shell
+	// execute. A machine absent is not free: no record of a pass is no pass.
+	RootFree map[string]bool
 }
 
 // Users is every user the composed file should contain, in the order it will be written.