fix(media): 对齐 EasyAI 媒体响应与转存策略

统一媒体异步提交和轮询响应，扩展 /ai/result 到当前用户的 Gateway 媒体任务，并保持既有 Gateway 字段兼容。\n\n启用转存但无可用渠道时回退到 24 小时本地静态资源；关闭转存时保留图片、音频等上游 Base64 字段。同步更新文件上传兼容结构、OpenAPI、管理端说明和回归测试。\n\n验证：cd apps/api && env -u AI_GATEWAY_TEST_DATABASE_URL go test ./... -count=1；gofmt -l 无输出；pnpm nx run web:typecheck。

apps/api/internal/httpapi/volces_compat_handlers.go

@@ -143,11 +143,11 @@ func (s *Server) deleteVolcesContentsGenerationTask(w http.ResponseWriter, r *ht
 // createLegacyVolcesVideoGeneration godoc
 // @Summary 创建 server-main 兼容视频任务
 // @Description 兼容 server-main 的 /api/v1/video/generations，返回 submitted 和 task_id；额外保留火山任务字段。
-// @Tags volces-compatible
+// @Tags media
 // @Accept json
 // @Produce json
 // @Security BearerAuth
-// @Success 200 {object} map[string]any
+// @Success 200 {object} TaskAcceptedResponse
 // @Router /api/v1/video/generations [post]
 func (s *Server) createLegacyVolcesVideoGeneration(w http.ResponseWriter, r *http.Request) {
 	user, ok := auth.UserFromContext(r.Context())
@@ -166,35 +166,40 @@ func (s *Server) createLegacyVolcesVideoGeneration(w http.ResponseWriter, r *htt
 		return
 	}
 	response := volcesCompatibleTask(task)
-	response["status"] = "submitted"
-	response["task_id"] = task.ID
-	writeJSON(w, http.StatusOK, response)
+	writeJSON(w, http.StatusOK, easyAITaskAcceptedResponseWithExtensions(task, response))
 }
 
-// getLegacyVolcesVideoResult godoc
-// @Summary 查询 server-main 兼容视频结果
-// @Tags volces-compatible
+// getEasyAITaskResult godoc
+// @Summary 查询 server-main EasyAIClient 兼容任务结果
+// @Description 查询当前用户的图片、视频、音频、视频高清和矢量化任务，并返回 EasyAI GeneratedResponse 兼容结构。
+// @Tags tasks
 // @Produce json
 // @Security BearerAuth
 // @Param taskID path string true "任务 ID"
-// @Success 200 {object} map[string]any
+// @Success 200 {object} EasyAIGeneratedResponse
+// @Failure 404 {object} EasyAIGeneratedResponse
 // @Router /api/v1/ai/result/{taskID} [get]
-func (s *Server) getLegacyVolcesVideoResult(w http.ResponseWriter, r *http.Request) {
-	task, ok := s.volcesCompatibleTaskForUser(w, r)
-	if !ok {
+func (s *Server) getEasyAITaskResult(w http.ResponseWriter, r *http.Request) {
+	user, ok := auth.UserFromContext(r.Context())
+	if !ok || user == nil {
+		writeEasyAIAsyncError(w, http.StatusUnauthorized, "unauthorized", nil, "unauthorized")
 		return
 	}
-	compat := volcesCompatibleTask(task)
-	legacyStatus := "process"
-	switch compat["status"] {
-	case "succeeded":
-		legacyStatus = "success"
-	case "failed", "cancelled":
-		legacyStatus = "failed"
+	task, err := s.store.GetTask(r.Context(), strings.TrimSpace(r.PathValue("taskID")))
+	if err != nil {
+		if store.IsNotFound(err) {
+			writeEasyAIAsyncError(w, http.StatusNotFound, "task not found", nil, "not_found")
+			return
+		}
+		s.logger.Error("get EasyAI-compatible task failed", "error", err)
+		writeError(w, http.StatusInternalServerError, "get task failed", "internal_error")
+		return
 	}
-	writeJSON(w, http.StatusOK, map[string]any{
-		"status": legacyStatus, "task_id": task.ID, "data": compat["content"], "result": compat,
-	})
+	if !runner.TaskAccessibleToUser(task, user) {
+		writeEasyAIAsyncError(w, http.StatusNotFound, "task not found", nil, "not_found")
+		return
+	}
+	writeJSON(w, http.StatusOK, easyAITaskResultResponse(task))
 }
 
 func (s *Server) createVolcesCompatibleTask(r *http.Request, user *auth.User, body map[string]any) (store.GatewayTask, error) {