studio previews: re-enable previews for studio endponit

crates/service/job/inference_job/src/job/job_types/workflow/video_style_transfer/util/process_preview_updates.rs

@@ -338,7 +338,7 @@ impl PreviewProcessor {
             expected_frame_count: self.expected_frame_count,
             stage_complete: state.all_frames_uploaded(),
             frames: state.all_object_paths().iter().map(|object_path| {
-              let url_str = format!("{}/{}", base_url, object_path.get_full_object_path_str());
+              let url_str = format!("{}{}", base_url, object_path.get_full_object_path_str());
               Url::parse(&url_str).unwrap()
             }).collect()
           }

crates/service/web/storyteller_web/src/http_server/endpoints/workflows/enqueue/enqueue_studio_workflow_handler.rs

@@ -313,7 +313,7 @@ pub async fn enqueue_studio_workflow_handler(
     trim_start_seconds: None,
     trim_end_seconds: None,
     target_fps: None,
-    generate_fast_previews: Some(false),
+    generate_fast_previews: Some(true),
   };
 
   info!("Creating ComfyUI job record...");