feat(upload): 封面上传支持横版与前端压缩

- 新增 imageCompress 与 imagePresets，上传前按规格高质量等比压缩
- 短剧封面拆分为竖版/横版两个上传位，带建议尺寸提示
- 轮播图、创作者中心封面与分集封面接入压缩与提示

src/styles/business/creator-center.css

@@ -188,6 +188,19 @@
   gap: 10px;
 }
 
+.creator-cover-actions {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+
+.creator-cover-hint {
+  margin: 0;
+  color: #9a97a8;
+  font-size: 12px;
+  line-height: 1.4;
+}
+
 .creator-cover-preview {
   display: grid;
   place-content: center;

src/styles/business/drama-management.css

@@ -165,6 +165,19 @@
   line-height: 1.4;
 }
 
+.cover-block + .cover-block {
+  margin-top: 18px;
+  padding-top: 16px;
+  border-top: 1px dashed var(--el-border-color-lighter);
+}
+
+.cover-label {
+  margin: 0 0 8px;
+  color: var(--el-text-color-regular);
+  font-size: 13px;
+  font-weight: 600;
+}
+
 .cover-editor {
   display: flex;
   gap: 18px;
@@ -183,6 +196,12 @@
   background: var(--el-fill-color-lighter);
 }
 
+.cover-preview-card--landscape {
+  flex: 0 0 160px;
+  width: 160px;
+  height: 90px;
+}
+
 .cover-preview-card img {
   position: absolute;
   inset: 0;
@@ -297,6 +316,10 @@
     flex-basis: 128px;
   }
 
+  .cover-preview-card--landscape {
+    flex-basis: 160px;
+  }
+
   .cover-editor-meta {
     width: 100%;
   }