Det the dataset dropout for yue2

ui/src/app/jobs/new/SimpleJob.tsx

@@ -1420,6 +1420,14 @@ export default function SimpleJob({
                   // automaticallt add the controls for a new dataset
                   const controls = modelArch?.controls ?? [];
                   newDataset.controls = controls;
+                  // arch dataset defaults (datasets[x].*) apply to added datasets too, not just at arch switch
+                  for (const key in modelArch?.defaults ?? {}) {
+                    const marker = 'datasets[x].';
+                    const idx = key.indexOf(marker);
+                    if (idx !== -1) {
+                      (newDataset as any)[key.slice(idx + marker.length)] = modelArch!.defaults![key][0];
+                    }
+                  }
                   setJobConfig([...jobConfig.config.process[0].datasets, newDataset], 'config.process[0].datasets');
                 }}
                 className="w-full px-4 py-2 bg-gray-700 hover:bg-gray-600 rounded-lg transition-colors"

ui/src/app/jobs/new/options.tsx

@@ -1392,6 +1392,8 @@ export const modelArchs: ModelArch[] = [
       'config.process[0].model.qtype': ['qfloat8', 'qfloat8'],
       'config.process[0].sample': [defaultYue2SampleConfig, defaultSampleConfig],
       'config.process[0].datasets[x].cache_latents_to_disk': [true, true],
+      // blank captions break lyric following; the AR must always see the prefix
+      'config.process[0].datasets[x].caption_dropout_rate': [0, 0.05],
     },
     // native YuE2 prompt: style text, a [Lyrics] line, the lyrics
     hasMultiLinePrompts: true,