fix(kernel): drop removed config keys + add a runnable example

Running against the single liblogosdelivery library surfaced a config drift:
the consolidated WakuNodeConf strictly rejects unknown keys, and
common.WakuConfig still emitted `legacyStore` (removed upstream, and sent
unconditionally) and `host` (renamed to `listenAddress`). That failed node
creation, so every kernel test that starts a node failed. Reconcile the config:

- drop the LegacyStore field (and its two obsolete test references; the
  already-skipped TestCheckLegacyStore keeps compiling);
- map Host to the `listenAddress` JSON key.

Add examples/kernel: a small runnable check that drives the unified lifecycle
(logosdelivery_create_node/start/stop/destroy) and a few kernel ops (version,
listen addresses, is-online, relay subscribe/unsubscribe) over the single
library. `go run ./examples/kernel` prints OK.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

examples/kernel/main.go

@@ -0,0 +1,80 @@
+// Command kernel is a small runnable check that the bindings work against the
+// single liblogosdelivery library: it drives the unified node lifecycle
+// (logosdelivery_create_node/start/stop/destroy) and a few low-level Kernel
+// (waku_*) operations through pkg/kernel.
+//
+// Build/run requires liblogosdelivery at link time, e.g.:
+//
+//	export LOGOS_DELIVERY_DIR=/abs/path/to/logos-delivery   # built with `make liblogosdelivery`
+//	export CGO_CFLAGS="-I$LOGOS_DELIVERY_DIR/library"
+//	export CGO_LDFLAGS="-L$LOGOS_DELIVERY_DIR/build -Wl,-rpath,$LOGOS_DELIVERY_DIR/build"
+//	go run ./examples/kernel
+package main
+
+import (
+	"log"
+
+	"github.com/logos-messaging/logos-delivery-go-bindings/pkg/kernel"
+	"github.com/logos-messaging/logos-delivery-go-bindings/pkg/kernel/common"
+)
+
+func main() {
+	const clusterID = 16
+
+	// A single, isolated relay node — no bootstrap/discovery needed.
+	cfg := &common.WakuConfig{
+		Relay:              true,
+		ClusterID:          clusterID,
+		Shards:             []uint16{0},
+		NumShardsInNetwork: 8,
+		LogLevel:           "ERROR",
+	}
+
+	// StartWakuNode creates (logosdelivery_create_node) + starts
+	// (logosdelivery_start_node) the node, allocating a free TCP port.
+	node, err := kernel.StartWakuNode("kernel-example", cfg)
+	if err != nil {
+		log.Fatalf("start node: %v", err)
+	}
+	defer func() {
+		// logosdelivery_stop_node + logosdelivery_destroy
+		if err := node.StopAndDestroy(); err != nil {
+			log.Printf("stop/destroy: %v", err)
+		}
+	}()
+
+	// A few low-level kernel calls to prove the kernel surface links and runs
+	// over the single library.
+	version, err := node.Version() // waku_version
+	if err != nil {
+		log.Fatalf("version: %v", err)
+	}
+	log.Printf("node version: %s", version)
+
+	addrs, err := node.ListenAddresses() // waku_listen_addresses
+	if err != nil {
+		log.Fatalf("listen addresses: %v", err)
+	}
+	log.Printf("listening on: %v", addrs)
+
+	online, err := node.IsOnline() // waku_is_online
+	if err != nil {
+		log.Fatalf("is online: %v", err)
+	}
+	log.Printf("online: %v", online)
+
+	// Subscribe to / unsubscribe from a relay (pubsub) topic
+	// (waku_relay_subscribe / waku_relay_unsubscribe).
+	topic := kernel.FormatWakuRelayTopic(clusterID, 0)
+	if err := node.RelaySubscribe(topic); err != nil {
+		log.Fatalf("relay subscribe: %v", err)
+	}
+	log.Printf("subscribed to %s", topic)
+
+	if err := node.RelayUnsubscribe(topic); err != nil {
+		log.Fatalf("relay unsubscribe: %v", err)
+	}
+	log.Printf("unsubscribed from %s", topic)
+
+	log.Print("OK — single liblogosdelivery library: node lifecycle + kernel ops work")
+}

pkg/kernel/common/config.go

@@ -1,11 +1,12 @@
 package common
 
 type WakuConfig struct {
-	Host                        string           `json:"host,omitempty"`
+	// Host is the LibP2P listening address; the consolidated WakuNodeConf calls
+	// it listenAddress (the legacy `host` key was removed).
+	Host                        string           `json:"listenAddress,omitempty"`
 	Nodekey                     string           `json:"nodekey,omitempty"`
 	Relay                       bool             `json:"relay"`
 	Store                       bool             `json:"store,omitempty"`
-	LegacyStore                 bool             `json:"legacyStore"`
 	Storenode                   string           `json:"storenode,omitempty"`
 	StoreMessageRetentionPolicy string           `json:"storeMessageRetentionPolicy,omitempty"`
 	StoreMessageDbUrl           string           `json:"storeMessageDbUrl,omitempty"`

pkg/kernel/nwaku_test.go

@@ -672,7 +672,6 @@ func TestStore(t *testing.T) {
 		Shards:          []uint16{64},
 		Discv5UdpPort:   udpPort,
 		TcpPort:         tcpPort,
-		LegacyStore:     false,
 	}
 
 	senderNode, err := NewWakuNode(&senderNodeWakuConfig, "senderNode")
@@ -692,7 +691,6 @@ func TestStore(t *testing.T) {
 		Shards:          []uint16{64},
 		Discv5UdpPort:   udpPort,
 		TcpPort:         tcpPort,
-		LegacyStore:     false,
 	}
 	receiverNode, err := NewWakuNode(&receiverNodeWakuConfig, "receiverNode")
 	require.NoError(t, err)

pkg/kernel/store_test.go

@@ -837,7 +837,6 @@ func TestCheckLegacyStore(t *testing.T) {
 	node2Config := DefaultWakuConfig
 	node2Config.Relay = true
 	node2Config.Store = true
-	node2Config.LegacyStore = true
 
 	Debug("Creating Node2")
 	node2, err := StartWakuNode("Node2", &node2Config)