Give the uplink seat its verbs, staged until its holders serve them (hq ADR 0241)

What a machine resolves through and over which links had no tool: the
resolver file and its writer, and each link with its routes and resolvers,
are now verbs of node-uplink, the same whatever manages the network. A verb
required at once would refuse every holder before the catalogue could serve
it, and a stored one would be required by an older controller, so it is
staged: promised and routed, never stored, and not yet a condition of
holding.

internal/inventory/seats_test.go

@@ -156,3 +156,25 @@ func TestTheControllersVerbsInTheRowAreTheBinarys(t *testing.T) {
 		t.Fatal("a verb this binary adds was not added")
 	}
 }
+
+// A verb still staged (novox/hq ADR 0241) is never in the store's row: a controller older than it reads
+// the row and would require what no holder of its time serves.
+func TestAStagedVerbIsNotSeeded(t *testing.T) {
+	inv := ForTest(t)
+	if _, err := inv.SeedSeats(t.Context(), catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	// Seeded twice: the second widens, and must not add it either.
+	if _, err := inv.SeedSeats(t.Context(), catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	got, err := inv.Seats(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, s := range got {
+		if s.Name == "node-uplink" && len(s.Serves) != 0 {
+			t.Fatalf("the row keeps %v", s.Serves)
+		}
+	}
+}