feat(api-gateway): 添加content服务代理路由

main.go添加textbooks/chapters/knowledge-points/questions四组路由

config.go新增ContentServiceURL字段

docs: known-issues记录P4 content端到端验证经验

services/api-gateway/main.go

@@ -93,6 +93,21 @@ func main() {
 		api.Any("/homework/*path", coreEduHandler)
 		api.Any("/grades", coreEduHandler)
 		api.Any("/grades/*path", coreEduHandler)
+
+		// content 服务路由（教材/章节/知识点/题库）
+		contentProxy, err := proxy.NewProxy(cfg.ContentServiceURL)
+		if err != nil {
+			log.Fatalf("failed to create content proxy: %v", err)
+		}
+		contentHandler := proxy.ProxyHandler(contentProxy)
+		api.Any("/textbooks", contentHandler)
+		api.Any("/textbooks/*path", contentHandler)
+		api.Any("/chapters", contentHandler)
+		api.Any("/chapters/*path", contentHandler)
+		api.Any("/knowledge-points", contentHandler)
+		api.Any("/knowledge-points/*path", contentHandler)
+		api.Any("/questions", contentHandler)
+		api.Any("/questions/*path", contentHandler)
 	}
 
 	srv := &http.Server{