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/inventory/nodes.go

@@ -670,31 +670,39 @@ func sameFailure(a, b Doing) bool {
 // a clean apply clears both (novox/hq 04-ISSUES/065). The previous row is read first and the
 // comparison made here, so "the same" is a rule this package states rather than a jsonb equality
 // that would restart the count on a changed word in an error.
-func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) error {
+// **And whether this report was news**, which is what makes a fact about it worth stating (novox/hq
+// ADR 0134). A machine reconciles continuously and reports each time; the same outcome about the same
+// declaration is the same state said again, and a fact per report would be a fact per minute per
+// machine that tells nobody anything. Read here because the previous row is read here anyway.
+func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) (news bool, err error) {
 	failed, err := json.Marshal(d.Failed)
 	if err != nil {
-		return err
+		return false, err
+	}
+	var before Doing
+	var beforeFailed []byte
+	found := i.store.Pool().QueryRow(ctx,
+		`select outcome, refused, failed, failing_since, failures, coalesce(declared,'')
+		   from node_report where node = $1`,
+		node).Scan(&before.Outcome, &before.Refused, &beforeFailed, &before.Since, &before.Times,
+		&before.Declared)
+	switch {
+	case errors.Is(found, pgx.ErrNoRows):
+		news = true
+	case found != nil:
+		return false, found
+	default:
+		if err := json.Unmarshal(beforeFailed, &before.Failed); err != nil {
+			return false, err
+		}
+		news = before.Outcome != d.Outcome || before.Declared != d.Declared || !sameFailure(before, d)
 	}
 	var since *time.Time
 	times := 0
 	if d.Outcome != OutcomeApplied {
-		var before Doing
-		var beforeFailed []byte
-		err := i.store.Pool().QueryRow(ctx,
-			`select outcome, refused, failed, failing_since, failures from node_report where node = $1`,
-			node).Scan(&before.Outcome, &before.Refused, &beforeFailed, &before.Since, &before.Times)
-		switch {
-		case errors.Is(err, pgx.ErrNoRows):
-		case err != nil:
-			return err
-		default:
-			if err := json.Unmarshal(beforeFailed, &before.Failed); err != nil {
-				return err
-			}
-		}
 		now := time.Now()
 		since, times = &now, 1
-		if err == nil && sameFailure(before, d) && before.Since != nil {
+		if found == nil && sameFailure(before, d) && before.Since != nil {
 			since, times = before.Since, before.Times+1
 		}
 	}
@@ -707,7 +715,10 @@ func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) error
 		   declared = excluded.declared,
 		   failing_since = excluded.failing_since, failures = excluded.failures`,
 		node, d.Outcome, d.Refused, failed, d.Applied, d.Declared, since, times)
-	return err
+	if err != nil {
+		return false, err
+	}
+	return news, nil
 }
 
 // NotDoingWhatTheyWereTold is every machine whose last report was not a clean apply.