feat(ai): add local expert library

backend/internal/logic/ai/handlers.go

@@ -15,18 +15,38 @@ import (
 
 // SessionDTO 是普通项目 AI 会话的公开契约，不携带数据库主键或自动创建对象的 ID。
 type SessionDTO struct {
-	ID        string    `json:"id"`
-	ProjectID string    `json:"projectId"`
-	Title     string    `json:"title"`
-	Context   string    `json:"context"`
-	Status    string    `json:"status"`
-	CreatedAt time.Time `json:"createdAt"`
-	UpdatedAt time.Time `json:"updatedAt"`
+	ID        string            `json:"id"`
+	ProjectID string            `json:"projectId"`
+	Title     string            `json:"title"`
+	Context   string            `json:"context"`
+	Status    string            `json:"status"`
+	Expert    *ExpertSummaryDTO `json:"expert"`
+	CreatedAt time.Time         `json:"createdAt"`
+	UpdatedAt time.Time         `json:"updatedAt"`
 }
 
 type createSessionRequest struct {
-	Title   string `json:"title"`
-	Context string `json:"context"`
+	Title    string `json:"title"`
+	Context  string `json:"context"`
+	ExpertID string `json:"expertId"`
+}
+
+type ExpertSummaryDTO struct {
+	ID           string `json:"id"`
+	Slug         string `json:"slug"`
+	Category     string `json:"category"`
+	CategoryName string `json:"categoryName"`
+	Name         string `json:"name"`
+	Description  string `json:"description"`
+	Emoji        string `json:"emoji"`
+	Color        string `json:"color"`
+}
+
+type ExpertDetailDTO struct {
+	ExpertSummaryDTO
+	SystemPrompt  string `json:"systemPrompt"`
+	Source        string `json:"source"`
+	SourceLicense string `json:"sourceLicense"`
 }
 
 // Handler 注册受认证、受项目所有权保护的 AI 会话接口。
@@ -39,6 +59,8 @@ func NewHandler(service *SessionService) *Handler {
 }
 
 func (h *Handler) Register(router gin.IRouter) {
+	router.GET("/ai-experts", h.listExperts)
+	router.GET("/ai-experts/:id", h.getExpert)
 	router.GET("/projects/:id/ai-sessions", h.list)
 	router.POST("/projects/:id/ai-sessions", h.create)
 }
@@ -70,7 +92,7 @@ func (h *Handler) create(c *gin.Context) {
 		httpx.Error(c, http.StatusBadRequest, "invalid_request", "请求参数无效")
 		return
 	}
-	session, err := h.service.Create(userID, projectIdentity, input.Title, input.Context)
+	session, err := h.service.CreateWithExpert(userID, projectIdentity, input.Title, input.Context, input.ExpertID)
 	if err != nil {
 		writeAIError(c, err)
 		return
@@ -78,6 +100,35 @@ func (h *Handler) create(c *gin.Context) {
 	c.JSON(http.StatusCreated, sessionDTO(*session))
 }
 
+func (h *Handler) listExperts(c *gin.Context) {
+	experts, err := h.service.ListExperts(ExpertFilter{Category: c.Query("category"), Query: c.Query("q")})
+	if err != nil {
+		writeAIError(c, err)
+		return
+	}
+	items := make([]ExpertSummaryDTO, 0, len(experts))
+	for _, expert := range experts {
+		items = append(items, expertSummaryDTO(expert))
+	}
+	c.JSON(http.StatusOK, items)
+}
+
+func (h *Handler) getExpert(c *gin.Context) {
+	identity, ok := httpx.IdentityParam(c, "id")
+	if !ok {
+		return
+	}
+	expert, err := h.service.GetExpert(identity)
+	if err != nil {
+		writeAIError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, ExpertDetailDTO{
+		ExpertSummaryDTO: expertSummaryDTO(*expert),
+		SystemPrompt:     expert.SystemPrompt, Source: expert.Source, SourceLicense: expert.SourceLicense,
+	})
+}
+
 func aiRequestContext(c *gin.Context) (uint, string, bool) {
 	userID, ok := auth.CurrentUserID(c)
 	if !ok {
@@ -92,7 +143,7 @@ func aiRequestContext(c *gin.Context) (uint, string, bool) {
 }
 
 func sessionDTO(session models.SenlinAgentAISession) SessionDTO {
-	return SessionDTO{
+	dto := SessionDTO{
 		ID:        session.Identity,
 		ProjectID: session.ProjectIdentity,
 		Title:     session.Title,
@@ -101,10 +152,29 @@ func sessionDTO(session models.SenlinAgentAISession) SessionDTO {
 		CreatedAt: session.CreatedAt.UTC(),
 		UpdatedAt: session.UpdatedAt.UTC(),
 	}
+	if session.Expert != nil {
+		dto.Expert = expertSummaryPointer(*session.Expert)
+	}
+	return dto
+}
+
+func expertSummaryPointer(expert models.SenlinAgentAIExpert) *ExpertSummaryDTO {
+	dto := expertSummaryDTO(expert)
+	return &dto
+}
+
+func expertSummaryDTO(expert models.SenlinAgentAIExpert) ExpertSummaryDTO {
+	return ExpertSummaryDTO{
+		ID: expert.Identity, Slug: expert.Slug, Category: expert.Category,
+		CategoryName: expert.CategoryName, Name: expert.Name, Description: expert.Description,
+		Emoji: expert.Emoji, Color: expert.Color,
+	}
 }
 
 func writeAIError(c *gin.Context, err error) {
 	switch {
+	case errors.Is(err, ErrExpertNotFound):
+		httpx.Error(c, http.StatusNotFound, "expert_not_found", "专家不存在或已停用")
 	case errors.Is(err, gorm.ErrRecordNotFound):
 		httpx.Error(c, http.StatusNotFound, "not_found", "项目不存在或无权访问")
 	case errors.Is(err, ErrInvalidSession):