refactor(documents): rename document tree model

backend/internal/logic/projects/workspace.go

@@ -10,11 +10,11 @@ import (
 )
 
 type workspaceCounts struct {
-	inbox        int64
-	tasks        int64
-	aiSessions   int64
-	documents    int64
-	cronPlans    int64
+	inbox      int64
+	tasks      int64
+	aiSessions int64
+	documents  int64
+	cronPlans  int64
 }
 
 // Workspace 在确认项目归属后执行首屏聚合；后续子查询只接收已授权的内部主键。
@@ -90,7 +90,7 @@ func (s *Service) workspaceCounts(projectID uint) (workspaceCounts, error) {
 	if err := models.DBService.Model(&models.SaAISession{}).Where("project_id = ?", projectID).Count(&counts.aiSessions).Error; err != nil {
 		return counts, err
 	}
-	if err := models.DBService.Model(&models.SaDocument{}).Where("project_id = ?", projectID).Count(&counts.documents).Error; err != nil {
+	if err := models.DBService.Model(&models.SaDocumentTree{}).Where("project_id = ?", projectID).Count(&counts.documents).Error; err != nil {
 		return counts, err
 	}
 	if err := models.DBService.Model(&models.SaCronPlan{}).Where("project_id = ?", projectID).Count(&counts.cronPlans).Error; err != nil {
@@ -224,7 +224,7 @@ func (s *Service) workspaceAISessions(projectID uint, projectIdentity string) ([
 }
 
 func (s *Service) workspaceDocuments(projectID uint, projectIdentity string) ([]WorkspaceDocumentDTO, error) {
-	var documents []models.SaDocument
+	var documents []models.SaDocumentTree
 	if err := models.DBService.Where("project_id = ?", projectID).Order("updated_at desc, id desc").Limit(50).Find(&documents).Error; err != nil {
 		return nil, err
 	}