layer1: add namespace bootstrap step 11

pkg/utils/namespace_manager.go

@@ -14,6 +14,7 @@ type NamespaceManager interface {
 	Snapshot() []string
 	SnapshotRecords() []NamespaceRecord
 	Get(name string) (NamespaceRecord, bool)
+	Bootstrap(namespaces []string, source NamespaceSource, observedAt time.Time) []NamespaceRecord
 	Subscribe(subscriber NamespaceSubscriber)
 	SnapshotSubscribers() []string
 	Upsert(event NamespaceEvent) NamespaceRecord
@@ -40,6 +41,22 @@ func (m *inMemoryNamespaceManager) Subscribe(subscriber NamespaceSubscriber) {
 	m.subs[subscriber.Name()] = subscriber
 }
 
+func (m *inMemoryNamespaceManager) Bootstrap(namespaces []string, source NamespaceSource, observedAt time.Time) []NamespaceRecord {
+	records := make([]NamespaceRecord, 0, len(namespaces))
+	for _, namespace := range namespaces {
+		records = append(records, m.Upsert(NamespaceEvent{
+			Type:       NamespaceEventAdd,
+			Name:       namespace,
+			Source:     source,
+			ObservedAt: observedAt,
+		}))
+	}
+	sort.Slice(records, func(i, j int) bool {
+		return records[i].Name < records[j].Name
+	})
+	return records
+}
+
 func (m *inMemoryNamespaceManager) SnapshotSubscribers() []string {
 	m.mu.RLock()
 	defer m.mu.RUnlock()

pkg/utils/namespace_manager_test.go

@@ -137,4 +137,24 @@ func TestNamespaceManagerMarkPartStateDerivesPhase(t *testing.T) {
 	if record.Phase != NamespacePhaseFailed {
 		t.Fatalf("expected phase failed, got %s", record.Phase)
 	}
+}
+
+func TestNamespaceManagerBootstrap(t *testing.T) {
+	manager := NewNamespaceManager()
+	now := time.Now().UTC()
+	records := manager.Bootstrap([]string{"tenant-b", "tenant-a"}, NamespaceSourceBackfill, now)
+
+	if len(records) != 2 {
+		t.Fatalf("expected 2 bootstrap records, got %d", len(records))
+	}
+	if !reflect.DeepEqual([]string{"tenant-a", "tenant-b"}, manager.Snapshot()) {
+		t.Fatalf("expected manager snapshot to contain bootstrapped namespaces")
+	}
+	record, ok := manager.Get("tenant-a")
+	if !ok {
+		t.Fatalf("expected tenant-a after bootstrap")
+	}
+	if record.Source != NamespaceSourceBackfill {
+		t.Fatalf("expected bootstrap source backfill, got %s", record.Source)
+	}
 }