fix: 优化后端各模块 handler

- database_handler, knowledge_handler, model_handler
- neo4j_handler, sub_table_handler
- system_handler, upload_handler
- knowledge_service, upload_service

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/internal/handler/model_handler.go

@@ -17,7 +17,14 @@ func NewModelHandler(svc *service.ModelService) *ModelHandler {
 	return &ModelHandler{service: svc}
 }
 
-// List 获取列表
+// @Summary 获取模型列表
+// @Description 获取所有已添加的AI模型列表
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Success 200 {object} map[string]interface{}
+// @Failure 500 {object} map[string]string
+// @Router /model/list [get]
 func (h *ModelHandler) List(c *gin.Context) {
 	list, err := h.service.List()
 	if err != nil {
@@ -32,7 +39,15 @@ func (h *ModelHandler) List(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"list": list})
 }
 
-// GetByID 获取详情
+// @Summary 获取模型详情
+// @Description 根据ID获取模型详细信息
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Param id path string true "模型ID"
+// @Success 200 {object} model.ModelInfo
+// @Failure 404 {object} map[string]string
+// @Router /model/{id} [get]
 func (h *ModelHandler) GetByID(c *gin.Context) {
 	id := c.Param("id")
 	model, err := h.service.GetByID(id)
@@ -43,7 +58,16 @@ func (h *ModelHandler) GetByID(c *gin.Context) {
 	c.JSON(http.StatusOK, model)
 }
 
-// Create 创建
+// @Summary 添加模型
+// @Description 添加新的AI模型配置
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Param request body model.CreateModelRequest true "模型信息"
+// @Success 200 {object} map[string]interface{}
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /model/add [post]
 func (h *ModelHandler) Create(c *gin.Context) {
 	var req model.CreateModelRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
@@ -60,7 +84,17 @@ func (h *ModelHandler) Create(c *gin.Context) {
 	c.JSON(http.StatusOK, result)
 }
 
-// Update 更新
+// @Summary 更新模型
+// @Description 更新指定模型的信息
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Param id path string true "模型ID"
+// @Param request body model.UpdateModelRequest true "更新信息"
+// @Success 200 {object} map[string]interface{}
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /model/{id} [put]
 func (h *ModelHandler) Update(c *gin.Context) {
 	id := c.Param("id")
 	var req model.UpdateModelRequest
@@ -78,7 +112,15 @@ func (h *ModelHandler) Update(c *gin.Context) {
 	c.JSON(http.StatusOK, result)
 }
 
-// Delete 删除
+// @Summary 删除模型
+// @Description 删除指定的AI模型
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Param id path string true "模型ID"
+// @Success 200 {object} map[string]bool
+// @Failure 500 {object} map[string]string
+// @Router /model/{id} [delete]
 func (h *ModelHandler) Delete(c *gin.Context) {
 	id := c.Param("id")
 	err := h.service.Delete(id)
@@ -90,7 +132,16 @@ func (h *ModelHandler) Delete(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"success": true})
 }
 
-// Test 测试连接
+// @Summary 测试模型连接
+// @Description 测试AI模型连接是否正常
+// @Tags 模型管理
+// @Accept json
+// @Produce json
+// @Param request body model.TestModelRequest true "模型测试请求"
+// @Success 200 {object} map[string]interface{}
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /model/test [post]
 func (h *ModelHandler) Test(c *gin.Context) {
 	var req model.TestModelRequest
 	if err := c.ShouldBindJSON(&req); err != nil {