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

ZeroGPU requires GPU-decorated functions to be importable at startup.
Moved training imports from lazy (inside handler) to top-level.

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

app.py

@@ -85,6 +85,10 @@ else:
     )
 
 
+# ── Import GPU-decorated functions at top level for ZeroGPU detection ───────
+from pipeline.training import full_training_pipeline, extract_features, train_model
+
+
 # ── Training Tab ─────────────────────────────────────────────────────────────
 
 def train_voice_model(audio_file, model_name, epochs, progress=gr.Progress()):
@@ -97,8 +101,6 @@ def train_voice_model(audio_file, model_name, epochs, progress=gr.Progress()):
 
     model_name = model_name.strip().replace(" ", "_")
 
-    from pipeline.training import full_training_pipeline
-
     def progress_callback(value, desc):
         progress(value, desc=desc)