feat(albums): soft-delete albums (admin+owner, hidden & irreversible, both app entries)

契约 deleteAlbum（DELETE /albums/{albumId} → 204 幂等）+ status enum 'deleted'：
- 服务端：softDelete（canView 404→canManage 403 防枚举；乐观锁 claim +
  outbox album.updated priority=high + audit album.delete）；列表/详情/更新/
  成员/资产/分类/水印/照片/展示位绑定全部 deleted→404；公开端 cn
  （status!=='active'）与 ov（isAlbumVisibleOv）天然屏蔽；ov 副本经
  album.updated 载荷 status 直投自动下线
- Admin：列表表格操作「删除」+ 详情页头「删除相册」（确认含不可恢复说明）
- App：操作面板「删除相册」（红字、二次确认、成功退回列表并刷新）
- 验证：API 56/56、App 397/397（analyze 0）、admin typecheck/lint/test/build 绿

Co-Authored-By: Claude Code <noreply@anthropic.com>

services/api/test/public.e2e-spec.ts

@@ -255,6 +255,7 @@ describe('public (e2e)', () => {
     let disabledToken: string;
     let bannerToken: string;
     let noBannerToken: string;
+    let coverOnlyToken: string;
     let catAId: string;
     let catBId: string;
     let catZhOnlyId: string;
@@ -342,6 +343,24 @@ describe('public (e2e)', () => {
         translations: [{ locale: 'zh-CN', title: '无封面相册' }],
       });
       noBannerToken = noBanner.publicToken;
+
+      // 宣传图/封面共用（2026-09-23 决策）：仅 cover 相册 → banner 回退 cover。
+      const coverOnly = await seedAlbum({
+        alias: 'pub-coveronly',
+        translations: [{ locale: 'zh-CN', title: '仅封面相册' }],
+      });
+      coverOnlyToken = coverOnly.publicToken;
+      const coverOnlyKey = `${KEY_ROOT}/albums/${coverOnly.id}/assets/cover.jpg`;
+      await storage.put(coverOnlyKey, await makeJpeg(900, 300), 'image/jpeg');
+      await prisma.album_assets.create({
+        data: {
+          albumId: coverOnly.id,
+          kind: 'cover',
+          locale: null,
+          objectKey: coverOnlyKey,
+          state: 'effective',
+        },
+      });
     });
 
     it('locale=en → 200 translation=en 内容且 resolvedLocale=en；categories 同语言解析且按 sortOrder 升序', async () => {
@@ -446,6 +465,16 @@ describe('public (e2e)', () => {
       expect(without.body.banner).toBeNull();
     });
 
+    it('banner 回退 cover（宣传图/封面共用：仅 cover 相册 → banner=cover 对象）', async () => {
+      const res = await getPublic(coverOnlyToken);
+      expect(res.status).toBe(200);
+      const banner = res.body.banner as { url: string; expiresAt: string };
+      expect(banner).not.toBeNull();
+      const fetched = await fetch(banner.url);
+      expect(fetched.status).toBe(200);
+      expect(fetched.headers.get('content-type')).toBe('image/jpeg');
+    });
+
     it('viewCount P1a 占位 null；startAt/endAt ISO + timezone 返回', async () => {
       const res = await getPublic(mainToken);
       expect(res.status).toBe(200);