A held module is in status, and it stops the mesh reading as well

novox/hq 04-ISSUES/125. A module assigned to a machine and never taken
runs none of what it declares. Status had no vocabulary for it: the
machine was heard from, current, and doing what it was told, so the mesh
printed "all doing what they were told" — which was true, and was acted
on, and every public name on the machine went dark.

Status now names each module a machine is holding rather than running,
per machine and with a count, read from what the MACHINE reported rather
than from the mesh's take-time listing — the machine is the only thing
that knows what it found. The JSON form carries the same rows, absent
rather than empty when nothing is held.

And a hold suppresses the all-well sentence, where being adopted does
not: adopted is a mode somebody chose, a module assigned and never taken
is a half-finished action with nothing left to finish it. The condition
is now a named function so the rule lives in one place and a test binds
to the real thing rather than a copy of it.

untakenModules raises a read it cannot make rather than answering "holding
nothing" from a failed query, which is the shape this whole issue is.

cmd/mesh-controller/readable.go

@@ -56,6 +56,23 @@ type meshStatus struct {
 	Machines int `json:"machines"`
 	// Adopted is every node still adopted (novox/hq ADR 0100); absent when none is.
 	Adopted []string `json:"adopted,omitempty"`
+	// Untaken is every module assigned to a machine that is holding what it found rather than
+	// running what the module declares, because nothing took it (novox/hq 04-ISSUES/125). Absent
+	// when nothing is held.
+	//
+	// **A document without this said an outage was a well mesh.** Read from what each machine
+	// reported, so it is the machine's account and not the mesh's take-time listing.
+	Untaken []machineUntaken `json:"untaken,omitempty"`
+}
+
+// machineUntaken is one module a machine is holding rather than running, and how many resources of
+// it are held.
+type machineUntaken struct {
+	Node   string `json:"node"`
+	Module string `json:"module"`
+	// Held is how many of the module's resources the machine is keeping as it found them. Zero is
+	// impossible here: a module with nothing held is not in this list.
+	Held int `json:"held"`
 }
 
 type machineUnresolved struct {
@@ -136,6 +153,23 @@ func statusAsJSON(asked answers) ([]byte, error) {
 		Quiet: []machineQuiet{}, Behind: []moduleBehind{}, Waiting: []machineWaiting{},
 		Reported: []machineReported{}, Unresolved: []machineUnresolved{},
 		Network: asked.network, Adopted: adoptedNodes(nodes)}
+	// In a stated order, so two readings of an unchanged mesh are the same document.
+	untakenNodes := make([]string, 0, len(asked.untaken))
+	for name := range asked.untaken {
+		untakenNodes = append(untakenNodes, name)
+	}
+	sort.Strings(untakenNodes)
+	for _, name := range untakenNodes {
+		modules := make([]string, 0, len(asked.untaken[name]))
+		for m := range asked.untaken[name] {
+			modules = append(modules, m)
+		}
+		sort.Strings(modules)
+		for _, m := range modules {
+			out.Untaken = append(out.Untaken,
+				machineUntaken{Node: name, Module: m, Held: asked.untaken[name][m]})
+		}
+	}
 	for name := range asked.refused {
 		out.Unresolved = append(out.Unresolved, machineUnresolved{
 			Node: name, Problem: asked.refused[name]})