The mesh says what it applied, and the replay has an address it may use

The pipeline was observable from a merge to an artifact and went dark where it touched a machine: a
node's report is control traffic only the control plane reads, so nothing said which version a
machine runs, or that it refused to (novox/hq ADR 0134). The control plane now states both under the
seat it holds — a role's events belong to the role and keep their address when the holder is
replaced — and only when the report is news, because a machine reconciles every minute and a fact per
report would be a fact per minute per machine.

Whether a report is news is the store's answer: it holds the previous one, so the listener returns it
and the server states the fact. That also gives the catch-up replay a subject the controller may
publish: it was published as a module's event from a module called "control-plane", which does not
exist, so the controller's own account refused it and every catalogue that asked what it missed was
answered with nothing.

internal/broker/nats.go

@@ -181,6 +181,14 @@ func PermissionsFor(p Principal) (Permissions, error) {
 		for _, seat := range meshSeatsTheControllerUses {
 			pub = append(pub, "mesh.seat."+seat+".accept.>")
 		}
+		// **And what the mesh says it did** (novox/hq ADR 0134). The control plane states its own
+		// facts under the seat it holds, because a role's events belong to the role and keep their
+		// address while the holder is replaced. Named one by one rather than as a whole namespace:
+		// least authority, and a fact nothing states is authority nobody uses.
+		for _, event := range ControllerStates {
+			pub = append(pub, seatEventSubject(ControllerSeat, event))
+		}
+
 		// Every module's tools: **the control plane is the way in** (novox/hq ADR 0095). A person
 		// or an agent asks through it and every question passes one process where an audit
 		// belongs — so it, alone among principals, may call any tool by name. The first `ask` on

internal/broker/states_agreement_test.go

@@ -0,0 +1,30 @@
+package broker_test
+
+import (
+	"slices"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The facts the control plane states are named twice — in the grant that permits them and in the code
+// that states them — because `link` imports `broker` and the dependency cannot go the other way. So a
+// test keeps them agreeing: a subject the grant omits is refused at the moment the mesh has something
+// to say, and one the grant adds that nothing states is authority nobody uses.
+//
+// An external test package, because it may import both while neither imports the other.
+func TestTheFactsTheGrantPermitsAreTheFactsTheMeshStates(t *testing.T) {
+	if broker.ControllerSeat != link.MeshControllerSeat {
+		t.Fatalf("the grant is written for the %q seat and the mesh states its facts under %q",
+			broker.ControllerSeat, link.MeshControllerSeat)
+	}
+	for _, event := range []string{link.KeyApplied, link.KeyRefused, link.KeyBuiltBefore} {
+		if !slices.Contains(broker.ControllerStates, event) {
+			t.Errorf("the mesh states %q and its account may not publish it", event)
+		}
+	}
+	if len(broker.ControllerStates) != 3 {
+		t.Errorf("the grant permits %v, which is more than the mesh states", broker.ControllerStates)
+	}
+}

internal/broker/streams.go

@@ -160,6 +160,17 @@ func Overlaps() []string {
 // ack subject is derived from (nats.go: `$JS.ACK.<stream>.controller.>`).
 const ControllerName = "controller"
 
+// ControllerSeat is the role the control plane holds, and ControllerStates are the facts it states
+// under it (novox/hq ADR 0134).
+//
+// **Written here as well as in `link`, and a test keeps them agreeing.** `link` imports `broker`, so
+// `broker` cannot import `link`; a grant naming a subject the controller never publishes is authority
+// nobody uses, and a controller publishing one the grant omits is refused at the moment it has
+// something to say.
+const ControllerSeat = "mesh-controller"
+
+var ControllerStates = []string{"applied", "refused", "built-before"}
+
 // ControllerFollows are the events the controller reacts to: the catalogue saying a module's
 // current version moved, and a catalogue that has just started saying it may have missed builds.
 //

internal/broker/testdata/composed.conf

@@ -24,7 +24,7 @@ accounts {
     jetstream: enabled
     users = [
       { user: "controller", password: "$2a$11$cccccccccccccccccccccc", permissions: {
-        publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>"] }
+        publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>", "mesh.seat.mesh-controller.event.applied", "mesh.seat.mesh-controller.event.built-before", "mesh.seat.mesh-controller.event.refused"] }
         subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built"] }
         allow_responses: { max: 1, ttl: "1m" }
       } }