feat(storage): 统一二进制对象存储与公开错误

新增 Aliyun OSS 与 S3 协议、通道内重试和按优先级跨通道切换，保留 server-main 兼容与环境 OSS 内存通道。

将请求及结果中的 Base64、Data URI、Buffer、multipart 和内联二进制统一对象化，生产路径不再写入本机静态目录，历史本地资源仅保留只读兼容。

引入 PublicErrorV1 并统一 API、异步查询、兼容协议和失败回调的安全错误输出，同时补充迁移、管理端、指标、OpenAPI 与本地模拟验收。

验证：go test ./... -count=1；go vet ./...；pnpm lint；pnpm test；pnpm build；pnpm openapi；tests/ci/migrations-test.sh。

apps/api/internal/httpapi/easyai_compat.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/easyai/easyai-ai-gateway/apps/api/internal/publicerror"
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/runner"
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
 )
@@ -58,14 +59,21 @@ func writeEasyAIAsyncError(w http.ResponseWriter, status int, message string, de
 	if len(codes) > 0 {
 		code = strings.TrimSpace(codes[0])
 	}
+	standard := publicerror.FromFields(code, message, status, status == http.StatusRequestTimeout || status == http.StatusTooManyRequests || status >= 500)
+	standard = publicErrorWithRetryAfter(standard, details)
+	publicerror.Observe(standard)
+	status, message, code = standard.HTTPStatus, standard.Message, standard.Code
 	errorPayload := map[string]any{
-		"message": message,
-		"status":  status,
+		"message":    message,
+		"status":     status,
+		"code":       code,
+		"category":   standard.Category,
+		"httpStatus": standard.HTTPStatus,
+		"retryable":  standard.Retryable,
+		"action":     standard.Action,
+		"version":    standard.Version,
 	}
-	if code != "" {
-		errorPayload["code"] = code
-	}
-	for key, value := range details {
+	for key, value := range safePublicErrorDetails(details, standard, false) {
 		errorPayload[key] = value
 	}
 	response := map[string]any{
@@ -158,8 +166,14 @@ func easyAITaskResultResponse(task store.GatewayTask) map[string]any {
 	if message != "" {
 		response["message"] = message
 	}
-	if code := firstNonEmpty(task.ErrorCode, easyAIString(cleanResult["code"])); code != "" {
-		response["code"] = code
+	if code := firstNonEmpty(task.ErrorCode, easyAIString(cleanResult["code"])); code != "" || status == "failed" {
+		standard := publicTaskError(task)
+		if code != "" && task.ErrorCode == "" {
+			standard = publicerror.WithIDs(publicerror.FromFields(code, message, 0, false), task.RequestID, task.ID)
+		}
+		response["code"] = standard.Code
+		response["message"] = standard.Message
+		response["error"] = standard
 	}
 	return response
 }