feat(knowledge): 饲养阶段风险提示接口与种子数据（#13）

server-go/internal/handler/knowledge.go

@@ -28,9 +28,45 @@ func RegisterKnowledgeRoutes(rg *gin.RouterGroup, db *gorm.DB, s3 *service.S3Ser
 	rg.PATCH("/knowledge/articles/:id", write, updateArticle(db))
 	rg.DELETE("/knowledge/articles/:id", write, deleteArticle(db))
 
+	rg.GET("/knowledge/stage-hints", read, listStageHints(db))
+
 	registerKnowledgeImageRoute(rg, db, s3, imageBucket)
 }
 
+// listStageHints 饲养阶段风险提示（?stage= 过滤；GET 天然幂等）
+func listStageHints(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		hints, err := model.StageHintsByStage(c.Query("stage"))
+		if err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+		resp := make([]gin.H, 0, len(hints))
+		for _, h := range hints {
+			diseases := make([]gin.H, 0, len(h.Diseases))
+			for _, dh := range h.Diseases {
+				id := ""
+				var d model.Disease
+				if db.Where("name = ?", dh.Name).First(&d).Error == nil {
+					id = d.ID
+				}
+				diseases = append(diseases, gin.H{
+					"id":     id,
+					"name":   dh.Name,
+					"reason": dh.Reason,
+				})
+			}
+			resp = append(resp, gin.H{
+				"stage":    h.Stage,
+				"label":    h.Label,
+				"summary":  h.Summary,
+				"diseases": diseases,
+			})
+		}
+		c.JSON(http.StatusOK, resp)
+	}
+}
+
 // listDiseases 蚕病百科列表（支持 category/keyword/enabled 过滤）
 func listDiseases(db *gorm.DB) gin.HandlerFunc {
 	return func(c *gin.Context) {