refactor: Remove default model handling from model settings and service

- Eliminated the 'isDefault' field from model settings and related service logic, simplifying model management.
- Updated UI components to remove references to default models, ensuring a cleaner user experience.
- Adjusted backend model creation and update processes to reflect the removal of default model selection logic.

frontend/src/views/settings/ModelSettings.vue

@@ -45,7 +45,6 @@
             <div class="model-name">
               {{ model.name }}
               <t-tag v-if="model.isBuiltin" theme="primary" size="small">内置</t-tag>
-              <t-tag v-if="model.isDefault" theme="success" size="small">{{ $t('common.default') }}</t-tag>
             </div>
             <div class="model-meta">
               <span class="source-tag">{{ model.source === 'local' ? 'Ollama' : $t('modelSettings.source.remote') }}</span>
@@ -95,7 +94,6 @@
             <div class="model-name">
               {{ model.name }}
               <t-tag v-if="model.isBuiltin" theme="primary" size="small">内置</t-tag>
-              <t-tag v-if="model.isDefault" theme="success" size="small">{{ $t('common.default') }}</t-tag>
             </div>
             <div class="model-meta">
               <span class="source-tag">{{ model.source === 'local' ? 'Ollama' : $t('modelSettings.source.remote') }}</span>
@@ -146,7 +144,6 @@
             <div class="model-name">
               {{ model.name }}
               <t-tag v-if="model.isBuiltin" theme="primary" size="small">内置</t-tag>
-              <t-tag v-if="model.isDefault" theme="success" size="small">{{ $t('common.default') }}</t-tag>
             </div>
             <div class="model-meta">
               <span class="source-tag">{{ model.source === 'local' ? 'Ollama' : $t('modelSettings.source.remote') }}</span>
@@ -196,7 +193,6 @@
             <div class="model-name">
               {{ model.name }}
               <t-tag v-if="model.isBuiltin" theme="primary" size="small">内置</t-tag>
-              <t-tag v-if="model.isDefault" theme="success" size="small">{{ $t('common.default') }}</t-tag>
             </div>
             <div class="model-meta">
               <span class="source-tag">{{ model.source === 'local' ? 'Ollama' : $t('modelSettings.source.openaiCompatible') }}</span>
@@ -295,7 +291,6 @@ function convertToLegacyFormat(model: ModelConfig) {
     baseUrl: model.parameters.base_url || '',
     apiKey: model.parameters.api_key || '',
     dimension: model.parameters.embedding_parameters?.dimension,
-    isDefault: model.is_default || false,
     isBuiltin: model.is_builtin || false
   }
 }
@@ -316,12 +311,6 @@ function deduplicateModels(models: any[]) {
     })
     
     if (seen.has(signature)) {
-      // 如果已经存在相同的模型，优先保留默认模型
-      const existing = seen.get(signature)
-      if (model.isDefault && !existing.isDefault) {
-        seen.set(signature, model)
-        return true
-      }
       return false
     }
     
@@ -417,8 +406,7 @@ const handleModelSave = async (modelData: any) => {
             truncate_prompt_tokens: 0
           }
         } : {})
-      },
-      is_default: modelData.isDefault || false
+      }
     }
 
     if (editingModel.value && editingModel.value.id) {
@@ -459,44 +447,15 @@ const deleteModel = async (type: 'chat' | 'embedding' | 'rerank' | 'vllm', model
   }
 }
 
-// 设为默认
-const setDefault = async (type: 'chat' | 'embedding' | 'rerank' | 'vllm', modelId: string) => {
-  try {
-    // 更新模型的 is_default 字段
-    await updateModelAPI(modelId, { is_default: true })
-    MessagePlugin.success(t('modelSettings.toasts.setDefault'))
-    // 重新加载模型列表
-    await loadModels()
-  } catch (error: any) {
-    console.error('设置默认模型失败:', error)
-    MessagePlugin.error(error.message || t('modelSettings.toasts.setDefaultFailed'))
-  }
-}
-
 // 获取模型操作菜单选项
 const getModelOptions = (type: 'chat' | 'embedding' | 'rerank' | 'vllm', model: any) => {
   const options: any[] = []
   
-  // 内置模型不能编辑和删除，只能设为默认
+  // 内置模型不能编辑和删除
   if (model.isBuiltin) {
-    // 如果不是默认模型，显示"设为默认"选项
-    if (!model.isDefault) {
-      options.push({
-        content: t('modelSettings.actions.setDefault'),
-        value: `set-default-${type}-${model.id}`
-      })
-    }
     return options
   }
   
-  // 如果不是默认模型，显示"设为默认"选项
-  if (!model.isDefault) {
-    options.push({
-      content: t('modelSettings.actions.setDefault'),
-      value: `set-default-${type}-${model.id}`
-    })
-  }
-  
   // 编辑选项
   options.push({
     content: t('common.edit'),
@@ -517,9 +476,7 @@ const getModelOptions = (type: 'chat' | 'embedding' | 'rerank' | 'vllm', model:
 const handleMenuAction = (data: { value: string }, type: 'chat' | 'embedding' | 'rerank' | 'vllm', model: any) => {
   const value = data.value
   
-  if (value.indexOf('set-default-') === 0) {
-    setDefault(type, model.id)
-  } else if (value.indexOf('edit-') === 0) {
+  if (value.indexOf('edit-') === 0) {
     editModel(type, model)
   } else if (value.indexOf('delete-') === 0) {
     // 使用确认对话框进行确认

internal/application/service/model.go

@@ -36,18 +36,6 @@ func NewModelService(repo interfaces.ModelRepository, ollamaService *ollama.Olla
 func (s *modelService) CreateModel(ctx context.Context, model *types.Model) error {
 	logger.Infof(ctx, "Creating model: %s, type: %s, source: %s", model.Name, model.Type, model.Source)
 
-	// If this model is set as default, unset other default models of the same type
-	if model.IsDefault {
-		logger.Infof(ctx, "Model is set as default, clearing other default models of type: %s", model.Type)
-		if err := s.clearOtherDefaultModels(ctx, model.TenantID, model.Type, ""); err != nil {
-			logger.ErrorWithFields(ctx, err, map[string]interface{}{
-				"model_type": model.Type,
-				"tenant_id":  model.TenantID,
-			})
-			return err
-		}
-	}
-
 	// Handle remote models (e.g., OpenAI, Azure)
 	if model.Source == types.ModelSourceRemote {
 		logger.Info(ctx, "Remote model detected, setting status to active")
@@ -192,19 +180,6 @@ func (s *modelService) UpdateModel(ctx context.Context, model *types.Model) erro
 		return errors.New("builtin models cannot be updated")
 	}
 
-	// If this model is set as default, unset other default models of the same type
-	if model.IsDefault {
-		logger.Infof(ctx, "Model is set as default, clearing other default models of type: %s", model.Type)
-		if err := s.clearOtherDefaultModels(ctx, model.TenantID, model.Type, model.ID); err != nil {
-			logger.ErrorWithFields(ctx, err, map[string]interface{}{
-				"model_type": model.Type,
-				"tenant_id":  model.TenantID,
-				"model_id":   model.ID,
-			})
-			return err
-		}
-	}
-
 	// Update model in repository
 	err = s.repo.Update(ctx, model)
 	if err != nil {
@@ -371,24 +346,5 @@ func (s *modelService) GetChatModel(ctx context.Context, modelId string) (chat.C
 	return chatModel, nil
 }
 
-// clearOtherDefaultModels sets IsDefault to false for all models of the same type
-// except the one with the given ID (if excludeID is not empty)
-// This ensures only one default model exists per type per tenant
-// Uses batch update for better performance
-func (s *modelService) clearOtherDefaultModels(ctx context.Context, tenantID uint, modelType types.ModelType, excludeID string) error {
-	logger.Infof(ctx, "Clearing other default models for type: %s, tenant: %d, exclude: %s", modelType, tenantID, excludeID)
-
-	// Use batch update to clear default status for all models of this type (excluding the specified ID)
-	err := s.repo.ClearDefaultByType(ctx, tenantID, modelType, excludeID)
-	if err != nil {
-		logger.ErrorWithFields(ctx, err, map[string]interface{}{
-			"model_type": modelType,
-			"tenant_id":  tenantID,
-			"exclude_id": excludeID,
-		})
-		return err
-	}
-
-	logger.Infof(ctx, "Successfully cleared other default models for type: %s", modelType)
-	return nil
-}
+// Note: default model selection logic has been removed; models no longer
+// maintain a per-type default flag at the service layer.

internal/application/service/session.go

@@ -279,23 +279,18 @@ func (s *sessionService) GenerateTitle(ctx context.Context,
 	modelID := session.SummaryModelID
 	if modelID == "" {
 		logger.Info(ctx, "Session SummaryModelID is empty, trying to get default chat model")
-		// Try to get default KnowledgeQA model
+		// Try to get an available KnowledgeQA model
 		models, err := s.modelService.ListModels(ctx)
 		if err != nil {
 			logger.ErrorWithFields(ctx, err, nil)
 			return "", fmt.Errorf("failed to list models: %w", err)
 		}
-		// Find default KnowledgeQA model or first KnowledgeQA model
+		// Find first available KnowledgeQA model
 		for _, model := range models {
 			if model.Type == types.ModelTypeKnowledgeQA {
-				if model.IsDefault {
-					modelID = model.ID
-					logger.Infof(ctx, "Using default KnowledgeQA model: %s", modelID)
-					break
-				} else if modelID == "" {
-					modelID = model.ID
-					logger.Infof(ctx, "Using first available KnowledgeQA model: %s", modelID)
-				}
+				modelID = model.ID
+				logger.Infof(ctx, "Using first available KnowledgeQA model: %s", modelID)
+				break
 			}
 		}
 		if modelID == "" {

internal/handler/model.go

@@ -50,7 +50,6 @@ func hideSensitiveInfo(model *types.Model) *types.Model {
 			EmbeddingParameters: model.Parameters.EmbeddingParameters,
 			ParameterSize:       model.Parameters.ParameterSize,
 		},
-		IsDefault: model.IsDefault,
 		IsBuiltin: model.IsBuiltin,
 		Status:    model.Status,
 		CreatedAt: model.CreatedAt,
@@ -66,7 +65,6 @@ type CreateModelRequest struct {
 	Source      types.ModelSource     `json:"source" binding:"required"`
 	Description string                `json:"description"`
 	Parameters  types.ModelParameters `json:"parameters" binding:"required"`
-	IsDefault   bool                  `json:"is_default"`
 }
 
 // CreateModel handles the HTTP request to create a new model
@@ -103,7 +101,6 @@ func (h *ModelHandler) CreateModel(c *gin.Context) {
 		Source:      req.Source,
 		Description: req.Description,
 		Parameters:  req.Parameters,
-		IsDefault:   req.IsDefault,
 	}
 
 	if err := h.service.CreateModel(ctx, model); err != nil {
@@ -214,7 +211,6 @@ type UpdateModelRequest struct {
 	Name        string                `json:"name"`
 	Description string                `json:"description"`
 	Parameters  types.ModelParameters `json:"parameters"`
-	IsDefault   bool                  `json:"is_default"`
 	Source      types.ModelSource     `json:"source"`
 	Type        types.ModelType       `json:"type"`
 }
@@ -264,7 +260,6 @@ func (h *ModelHandler) UpdateModel(c *gin.Context) {
 	if req.Parameters != (types.ModelParameters{}) {
 		model.Parameters = req.Parameters
 	}
-	model.IsDefault = req.IsDefault
 	model.Source = req.Source
 	model.Type = req.Type