fix: address project audit gaps

backend/internal/search/service_test.go

@@ -24,3 +24,27 @@ func TestSearchFindsNoteBody(t *testing.T) {
 	require.Len(t, results, 1)
 	require.Equal(t, "note", results[0].Type)
 }
+
+func TestSearchFindsCoreProjectObjects(t *testing.T) {
+	database, err := gorm.Open(sqlite.Open(fmt.Sprintf("file:%s?mode=memory&cache=shared", t.Name())), &gorm.Config{})
+	require.NoError(t, err)
+	require.NoError(t, domain.AutoMigrate(database))
+	require.NoError(t, database.Create(&domain.Project{ID: 1, OwnerID: 7, Name: "支付项目"}).Error)
+	require.NoError(t, database.Create(&domain.Task{ProjectID: 1, CreatedBy: 7, Title: "回调任务", Description: "检查 webhook"}).Error)
+	require.NoError(t, database.Create(&domain.Source{ProjectID: 1, CreatedBy: 7, Kind: "link", Title: "支付文档", URL: "https://example.com/pay", ContentText: "webhook 签名"}).Error)
+	require.NoError(t, database.Create(&domain.InboxItem{ProjectID: 1, CreatedBy: 7, SourceType: "text", Title: "收集项", Body: "webhook 待整理"}).Error)
+	require.NoError(t, database.Create(&domain.AISession{ProjectID: 1, CreatedBy: 7, Title: "AI 分析", Context: "webhook 问答"}).Error)
+
+	service := NewService(database)
+	results, err := service.Search(7, "webhook")
+
+	require.NoError(t, err)
+	types := make(map[string]bool)
+	for _, result := range results {
+		types[result.Type] = true
+	}
+	require.True(t, types["task"])
+	require.True(t, types["source"])
+	require.True(t, types["inbox"])
+	require.True(t, types["ai_session"])
+}