layer1: add namespace manager bridge step 12

doc/thinking/2026-04-26-namespace-manager-step12.md

@@ -0,0 +1,17 @@
+# 2026-04-26 — NamespaceManager rewrite, step 12
+
+## Цель шага
+
+Добавить bridge helper между legacy `NamespaceResolver` и новым `NamespaceManager`.
+
+## Что меняем
+
+1. Добавляем helper `NewBootstrappedNamespaceManager()`.
+2. Helper берёт snapshot из resolver и bootstraps manager.
+3. Добавляем unit test на bootstrap from resolver.
+
+## Что НЕ меняем
+
+- не подключаем helper к production startup path;
+- не меняем watcher-ы;
+- не меняем runtime components.

pkg/utils/namespace_manager.go

@@ -35,6 +35,15 @@ func NewNamespaceManager() NamespaceManager {
 	}
 }
 
+func NewBootstrappedNamespaceManager(resolver *NamespaceResolver, source NamespaceSource, observedAt time.Time) NamespaceManager {
+	manager := NewNamespaceManager()
+	if resolver == nil {
+		return manager
+	}
+	manager.Bootstrap(resolver.Snapshot(), source, observedAt)
+	return manager
+}
+
 func (m *inMemoryNamespaceManager) Subscribe(subscriber NamespaceSubscriber) {
 	m.mu.Lock()
 	defer m.mu.Unlock()

pkg/utils/namespace_manager_test.go

@@ -157,4 +157,25 @@ func TestNamespaceManagerBootstrap(t *testing.T) {
 	if record.Source != NamespaceSourceBackfill {
 		t.Fatalf("expected bootstrap source backfill, got %s", record.Source)
 	}
+}
+
+func TestNewBootstrappedNamespaceManager(t *testing.T) {
+	resolver := &NamespaceResolver{
+		FissionResourceNS: map[string]string{
+			"tenant-b": "tenant-b",
+			"tenant-a": "tenant-a",
+		},
+	}
+
+	manager := NewBootstrappedNamespaceManager(resolver, NamespaceSourceEnv, time.Now().UTC())
+	if !reflect.DeepEqual([]string{"tenant-a", "tenant-b"}, manager.Snapshot()) {
+		t.Fatalf("expected bootstrapped manager snapshot from resolver")
+	}
+	record, ok := manager.Get("tenant-a")
+	if !ok {
+		t.Fatalf("expected tenant-a in bootstrapped manager")
+	}
+	if record.Source != NamespaceSourceEnv {
+		t.Fatalf("expected env source, got %s", record.Source)
+	}
 }