fix(memo): merge scoped and legacy topics in ListTopics

internal/memo/store.go

@@ -184,6 +184,7 @@ func (s *FileStore) ListTopics(ctx context.Context, scope Scope) ([]string, erro
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
+	seen := make(map[string]struct{})
 	for _, dir := range s.topicsDirs(scope) {
 		entries, err := os.ReadDir(dir)
 		if err != nil {
@@ -192,14 +193,22 @@ func (s *FileStore) ListTopics(ctx context.Context, scope Scope) ([]string, erro
 			}
 			return nil, fmt.Errorf("memo: list topics: %w", err)
 		}
-		if names := collectTopicNames(entries); len(names) > 0 {
-			return names, nil
+		for _, name := range collectTopicNames(entries) {
+			seen[name] = struct{}{}
 		}
 	}
-	return nil, nil
+	if len(seen) == 0 {
+		return nil, nil
+	}
+	names := make([]string, 0, len(seen))
+	for name := range seen {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names, nil
 }
 
-// collectTopicNames 将目录项过滤为 topic 文件名列表，并按字典序排序保证稳定输出。
+// collectTopicNames 将目录项过滤为 topic 文件名列表。
 func collectTopicNames(entries []os.DirEntry) []string {
 	names := make([]string, 0, len(entries))
 	for _, entry := range entries {
@@ -208,7 +217,6 @@ func collectTopicNames(entries []os.DirEntry) []string {
 		}
 		names = append(names, entry.Name())
 	}
-	sort.Strings(names)
 	return names
 }
 

internal/memo/store_test.go

@@ -268,6 +268,41 @@ func TestFileStoreLoadTopicAndListTopicsFallbackToLegacyProjectPath(t *testing.T
 	}
 }
 
+func TestFileStoreListTopicsMergesScopedAndLegacyProjectTopics(t *testing.T) {
+	store, legacyDir := newLegacyProjectStore(t)
+	scopedTopicsDir := store.topicsDir(ScopeProject)
+	legacyTopicsDir := filepath.Join(legacyDir, topicsDirName)
+	if err := os.MkdirAll(scopedTopicsDir, 0o755); err != nil {
+		t.Fatalf("MkdirAll(scoped topics) error = %v", err)
+	}
+	if err := os.MkdirAll(legacyTopicsDir, 0o755); err != nil {
+		t.Fatalf("MkdirAll(legacy topics) error = %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(scopedTopicsDir, "scoped.md"), []byte("scoped"), 0o644); err != nil {
+		t.Fatalf("WriteFile(scoped topic) error = %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(legacyTopicsDir, "legacy.md"), []byte("legacy"), 0o644); err != nil {
+		t.Fatalf("WriteFile(legacy topic) error = %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(legacyTopicsDir, "scoped.md"), []byte("legacy dup"), 0o644); err != nil {
+		t.Fatalf("WriteFile(legacy duplicate topic) error = %v", err)
+	}
+
+	topics, err := store.ListTopics(context.Background(), ScopeProject)
+	if err != nil {
+		t.Fatalf("ListTopics() error = %v", err)
+	}
+	want := []string{"legacy.md", "scoped.md"}
+	if len(topics) != len(want) {
+		t.Fatalf("len(topics) = %d, want %d, topics = %#v", len(topics), len(want), topics)
+	}
+	for i := range want {
+		if topics[i] != want[i] {
+			t.Fatalf("topics[%d] = %q, want %q (topics=%#v)", i, topics[i], want[i], topics)
+		}
+	}
+}
+
 func TestFileStoreSaveIndexMigratesLegacyProjectData(t *testing.T) {
 	store, legacyDir := newLegacyProjectStore(t)
 	legacyTopicsDir := filepath.Join(legacyDir, topicsDirName)