enhance(server): 動画サムネイルの縦の長さを最大422pxにする

Related to #10149
Related to #10450

packages/backend/src/core/VideoProcessingService.ts

@@ -37,7 +37,7 @@ export class VideoProcessingService {
 					});
 			});
 
-			return await this.imageProcessingService.convertToWebp(`${dir}/out.png`, 498, 280);
+			return await this.imageProcessingService.convertToWebp(`${dir}/out.png`, 498, 422);
 		} finally {
 			cleanup();
 		}