fix: add input validation and cpu() guard in OmniVoiceGenerate

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

nodes/generator.py

@@ -33,12 +33,17 @@ class OmniVoiceGenerate:
     def generate(self, model, text, mode, ref_audio=None, ref_text="", instruct="", speed=1.0, num_step=32):
         kwargs = {"text": text, "speed": speed, "num_step": num_step}
 
+        if mode == "voice_cloning" and ref_audio is None:
+            raise ValueError("voice_cloning mode requires ref_audio to be connected")
+        if mode == "voice_design" and not instruct:
+            raise ValueError("voice_design mode requires an instruct string (e.g. 'female, low pitch')")
+
         if mode == "voice_cloning" and ref_audio is not None:
             tmp = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)
             tmp_path = tmp.name
             tmp.close()
             try:
-                waveform = ref_audio["waveform"].squeeze(0)  # (channels, samples)
+                waveform = ref_audio["waveform"].squeeze(0).cpu()  # (channels, samples)
                 torchaudio.save(tmp_path, waveform, ref_audio["sample_rate"])
                 kwargs["ref_audio"] = tmp_path
                 if ref_text: