feat(gateway): admin 列表端点接真实数据——persona/session/memory 补 List() 并注入 gateway.Deps

根因：gateway.Server 定义 SessionStore/PersonaStore/MemoryStore 接口但生产从未满足：
- 底层 manager 无 List() 方法；
- wireFrontend 的 gateway.Deps{} 未传 Session/Personas/Memories。
→ /api/v1/sessions|personas 与 /api/v1/admin/{sessions,personas,memories} 恒返回 []。

改动：
- persona/registry：Registry.List() []Character（并发安全、值拷贝）。
- channel/session：SessionManager.List(ctx)（查 channel_sessions 表+按 actor_role 重建）。
- runtime/memory：Store.List(ctx)（全表，复用 scanItems）。
- gateway 三 Store 接口改为返回域类型（Character/MemoryItem），映射统一放 collect* 侧。
- cmd/cyrene/wire.go：Deps 补传 Session/Personas/Memories。
- .gitignore：cyrene→/cyrene（锚定根，不再误伤 cmd/cyrene 目录）。

实机验证：/api/v1/admin/personas 返回 {id:cyrene,name:昔涟,isDefault:true}。

internal/runtime/memory/store.go

@@ -246,6 +246,21 @@ func (s *Store) ListByPersona(ctx context.Context, personaID string) ([]MemoryIt
 	return scanItems(rows, "persona item")
 }
 
+// List returns every memory item, newest first, across all personas. It is the
+// aggregate/admin view that enumerates all persisted memory regardless of the
+// persona-isolation boundary; callers that must respect isolation should use
+// ListByPersona or ListScope instead. The returned slice is non-nil.
+func (s *Store) List(ctx context.Context) ([]MemoryItem, error) {
+	rows, err := s.db.QueryContext(ctx, `SELECT id, persona_id, role_id, project_id, scope, kind,
+		content, tags, confidence, source_conversation, created_at, updated_at,
+		decay_weight FROM memory_items
+		ORDER BY created_at DESC`)
+	if err != nil {
+		return nil, fmt.Errorf("memory: list items: %w", err)
+	}
+	return scanItems(rows, "item")
+}
+
 // scanItems reads every row into a MemoryItem slice, closing rows and wrapping
 // scan/iterate failures with the operation name. A non-nil, possibly empty slice
 // is always returned on success.

internal/runtime/memory/store_test.go

@@ -171,6 +171,45 @@ func TestStore_ListByPersona_MissingPersona_异常(t *testing.T) {
 	}
 }
 
+func TestStore_List_正常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	s := newTestStore(t)
+
+	// An empty store lists nothing but stays non-nil.
+	if got, err := s.List(ctx); err != nil || got == nil || len(got) != 0 {
+		t.Fatalf("List() on empty store = %#v, err=%v; want empty non-nil", got, err)
+	}
+
+	for _, item := range []MemoryItem{
+		{PersonaID: "persona.a", Content: "A 的记忆", Scope: ScopePersona, Kind: KindRelationship},
+		{PersonaID: "persona.b", Content: "B 的记忆", Scope: ScopePersona, Kind: KindWorldEvent},
+		{PersonaID: "persona.a", Content: "项目记忆", Scope: ScopeProject, Kind: KindWorldEvent, ProjectID: "proj.1"},
+	} {
+		if _, err := s.Add(ctx, item); err != nil {
+			t.Fatalf("Add(%s): %v", item.Content, err)
+		}
+	}
+
+	got, err := s.List(ctx)
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(got) != 3 {
+		t.Fatalf("List = %d items, want 3", len(got))
+	}
+	// Newest first (created_at DESC).
+	if got[0].Content != "项目记忆" {
+		t.Errorf("got[0].Content = %q, want the latest added (项目记忆)", got[0].Content)
+	}
+	if got[2].Content != "A 的记忆" {
+		t.Errorf("got[2].Content = %q, want the oldest (A 的记忆)", got[2].Content)
+	}
+	if got[0].Scope != ScopeProject || got[0].PersonaID != "persona.a" {
+		t.Errorf("project item fields = %+v", got[0])
+	}
+}
+
 func TestStore_Delete_正常(t *testing.T) {
 	t.Parallel()
 	ctx := context.Background()