Import all @spaces.GPU functions at top level for ZeroGPU detection

separate_audio and convert_voice were imported lazily, preventing
ZeroGPU from detecting them at startup. Now all GPU functions are
imported at module level.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -42,6 +42,8 @@ else:
 
 # ── Import GPU-decorated functions at top level for ZeroGPU detection ───────
 from pipeline.training import full_training_pipeline, extract_features, train_model
+from pipeline.separation import separate_audio
+from pipeline.inference import convert_voice
 
 
 # ── Training Tab ─────────────────────────────────────────────────────────────
@@ -112,8 +114,6 @@ def convert_song(
     if model_choice == "(aucun modèle entraîné)" or not model_choice:
         return "Erreur : Veuillez d'abord entraîner un modèle vocal.", None, None, None
 
-    from pipeline.separation import separate_audio
-    from pipeline.inference import convert_voice
     from pipeline.mixing import mix_audio
 
     try: