调整精选后端公开契约

新增精选活动卡图片 objectKey 存储字段和迁移兼容。

新增后台活动卡图片 OSS 直传凭证接口。

移除素材包精选分类约束，允许未设置分类素材进入全部精选。

同步 admin 和前台读取活动卡 objectKey 的类型契约。

apps/admin-web/src/api/adminApiTypes.ts

@@ -457,6 +457,7 @@ export interface AdminEditorShowcaseCampaignPayload {
   enabled: boolean;
   title: string;
   imageSrc: string;
+  imageObjectKey?: string | null;
   prompt: string;
   author: string;
   costText: string;
@@ -471,11 +472,37 @@ export interface AdminUpsertEditorShowcaseCampaignRequest {
   enabled: boolean;
   title: string;
   imageSrc: string;
+  imageObjectKey?: string | null;
   prompt: string;
   author: string;
   costText: string;
 }
 
+export interface AdminDirectUploadTicketPayload {
+  bucket: string;
+  host: string;
+  objectKey: string;
+  legacyPublicPath: string;
+  contentType?: string | null;
+  formFields: Record<string, string | null | undefined>;
+}
+
+export interface AdminCreateEditorShowcaseCampaignImageUploadTicketRequest {
+  fileName: string;
+  contentType: string;
+  contentLength: number;
+}
+
+export interface AdminCreateEditorShowcaseCampaignImageUploadTicketResponse {
+  upload: AdminDirectUploadTicketPayload;
+}
+
+export interface AdminUploadedEditorShowcaseCampaignImage {
+  imageSrc: string;
+  imageObjectKey: string;
+  legacyPublicPath: string;
+}
+
 export interface AdminUpsertProfileRedeemCodeRequest {
   code: string;
   mode: ProfileRedeemCodeMode;