Fix zone provisioning: seed glue + IP primaries

Two bugs made every provisioned zone fail to load:

1. The seed zone's apex NS (ns1.<zone>) is in-zone but had no address
   record, so BIND check-integrity refused to load it and rndc addzone
   reverted. Add a glue A record pointing at the primary pod IP.
2. Secondaries rendered primaries/default-primaries with the primary's
   DNS name, but BIND only accepts IP addresses there (it read the name
   as a remote-servers list and failed config load, crash-looping the
   secondary). Render the primary pod IP instead, and watch Pods so the
   config re-renders when that IP appears or changes.

- bind.WriteSeedZone writes 'ns1 IN A <primaryIP>' glue
- controllers resolve primaryPodIP and pass it to the seed (requeue if
  the primary has no IP yet)
- BindCluster renders PrimaryAddress from pod-0's IP and watches Pods
- render omits catalog primaries when the IP is unknown (no empty list)

internal/bind/render_test.go

@@ -53,6 +53,33 @@ func TestRenderCatalogOnSecondaryOnly(t *testing.T) {
 	}
 }
 
+func TestRenderCatalogOmittedWhenPrimaryIPUnknown(t *testing.T) {
+	// Primary IP not known yet and no explicit default-primaries: the secondary
+	// must not emit a catalog-zones / secondary catalog zone with an empty
+	// primaries list (which BIND rejects at config load).
+	in := RenderInput{
+		Cluster:        newCluster(bindv1alpha1.ModeAuthoritative),
+		Catalog:        &bindv1alpha1.BindCatalogZone{Spec: bindv1alpha1.BindCatalogZoneSpec{ZoneName: "catalog.internal"}},
+		PrimaryAddress: "",
+	}
+	_, secondary := RenderNamedConf(in)
+	if strings.Contains(secondary, "catalog-zones") || strings.Contains(secondary, "primaries {") {
+		t.Fatalf("secondary must omit catalog primaries when the primary IP is unknown:\n%s", secondary)
+	}
+}
+
+func TestRenderCatalogUsesPrimaryIP(t *testing.T) {
+	in := RenderInput{
+		Cluster:        newCluster(bindv1alpha1.ModeAuthoritative),
+		Catalog:        &bindv1alpha1.BindCatalogZone{Spec: bindv1alpha1.BindCatalogZoneSpec{ZoneName: "catalog.internal"}},
+		PrimaryAddress: "10.42.0.7",
+	}
+	_, secondary := RenderNamedConf(in)
+	if !strings.Contains(secondary, "primaries { 10.42.0.7; }") {
+		t.Fatalf("secondary should point primaries at the primary pod IP:\n%s", secondary)
+	}
+}
+
 func TestRenderACL(t *testing.T) {
 	in := RenderInput{
 		Cluster: newCluster(bindv1alpha1.ModeAuthoritative),