fix: uncheck train_on_completions for audio models

Pure audio models (orpheus, sparktts, whisper, sesame-csm) now
always have trainOnCompletions auto-unchecked when selected.
Gemma3n (audio_vlm) only unchecks when the dataset is audio.

- Add is_audio to frontend ModelConfigResponse (backend already returns it)
- Add isAudioModel state to training config store
- Auto-set trainOnCompletions=false for pure audio models on model load
- Auto-set trainOnCompletions=false for audio VLMs when dataset is audio
- Respect manual user override via existing _trainOnCompletionsManuallySet flag

studio/frontend/src/features/training/api/models-api.ts

@@ -61,8 +61,8 @@ export interface ModelConfigResponse {
   model_name?: string | null;
   config?: BackendModelConfig | null;
   is_vision: boolean;
+  is_audio: boolean;
   is_lora: boolean;
-  is_audio?: boolean;
   base_model?: string | null;
   model_type?: "text" | "vision" | "audio" | "embeddings" | null;
 }

studio/frontend/src/features/training/stores/training-config-store.ts

@@ -36,6 +36,7 @@ const initialState: TrainingConfigState = {
   uploadedFile: null,
   isCheckingVision: false,
   isVisionModel: false,
+  isAudioModel: false,
   isLoadingModelDefaults: false,
   modelDefaultsError: null,
   modelDefaultsAppliedFor: null,
@@ -58,6 +59,7 @@ let _trainOnCompletionsManuallySet = false;
 const NON_PERSISTED_STATE_KEYS: ReadonlySet<keyof TrainingConfigState> = new Set([
   "modelType",
   "isCheckingVision",
+  "isAudioModel",
   "isLoadingModelDefaults",
   "modelDefaultsError",
   "modelDefaultsAppliedFor",
@@ -127,6 +129,16 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
               patch.trainOnCompletions = false;
             }
 
+            const isAudio = !!modelDetails.is_audio;
+            // Pure audio model → always uncheck trainOnCompletions.
+            if (isAudio && !modelDetails.is_vision) {
+              patch.trainOnCompletions = false;
+            }
+            // Audio-capable vision model (e.g. gemma3n) + audio dataset → uncheck.
+            if (isAudio && modelDetails.is_vision && get().isDatasetAudio) {
+              patch.trainOnCompletions = false;
+            }
+
             // Use backend-provided model_type when available, otherwise
             // infer from is_vision (temporary until backend ships model_type).
             const inferredModelType: ModelType = modelDetails.model_type
@@ -136,6 +148,7 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
               ...patch,
               modelType: inferredModelType,
               isVisionModel: modelDetails.is_vision,
+              isAudioModel: isAudio,
               isLoadingModelDefaults: false,
               isCheckingVision: false,
               modelDefaultsError: null,
@@ -194,10 +207,13 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
               isCheckingDataset: false,
             };
             if (!_trainOnCompletionsManuallySet) {
-              const { isVisionModel } = get();
+              const { isVisionModel, isAudioModel } = get();
               if (isVisionModel && isImage) {
                 updates.trainOnCompletions = false;
               }
+              if (isAudioModel && isAudio) {
+                updates.trainOnCompletions = false;
+              }
             }
             set(updates);
           })
@@ -233,6 +249,7 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
             selectedModel: null,
             isCheckingVision: false,
             isVisionModel: false,
+            isAudioModel: false,
             isDatasetAudio: false,
             isLoadingModelDefaults: false,
             modelDefaultsError: null,
@@ -249,6 +266,7 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
             set({
               isCheckingVision: false,
               isVisionModel: false,
+              isAudioModel: false,
               isDatasetAudio: false,
               isLoadingModelDefaults: false,
               modelDefaultsError: null,

studio/frontend/src/features/training/types/config.ts

@@ -60,6 +60,7 @@ export interface TrainingConfigState {
   logFrequency: number;
   isCheckingVision: boolean;
   isVisionModel: boolean;
+  isAudioModel: boolean;
   isLoadingModelDefaults: boolean;
   modelDefaultsError: string | null;
   modelDefaultsAppliedFor: string | null;