Wire Qwen 2.1 as Generate-only engine with 25/1 sampler defaults.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/utils/studio2/size.ts

@@ -21,5 +21,5 @@ export async function resolveRequestSize(owner: string, request: any) {
     }
   }
   if (video && request.startClipId && !dimensions?.width) throw new Error('Cannot measure the previous clip.')
-  Object.assign(request.settings,resolveSize(request.settings.aspect,dimensions))
+  Object.assign(request.settings,resolveSize(request.settings.aspect,dimensions,undefined,request.engine))
 }