Fix build error

backend/omnivoice_adapter.py

@@ -7,6 +7,21 @@ import soundfile as sf
 
 from backend.types import VoiceConfig
 
+try:
+    import spaces
+except ImportError:
+    class _SpacesShim:
+        @staticmethod
+        def GPU(fn=None, **_kwargs):
+            def decorate(inner):
+                return inner
+
+            if fn is not None:
+                return decorate(fn)
+            return decorate
+
+    spaces = _SpacesShim()
+
 
 NARRATOR_PRESETS = {
     "brother-anselm": "male, warm baritone, measured, british accent",
@@ -48,6 +63,7 @@ class OmniVoiceAdapter:
         self._backend = "omnivoice"
         return self._model
 
+    @spaces.GPU(duration=300)
     def synthesize(
         self,
         *,

tests/test_zero_gpu.py

@@ -0,0 +1,26 @@
+import importlib
+import sys
+from types import SimpleNamespace
+
+
+def test_omnivoice_adapter_registers_zero_gpu_decorator(monkeypatch) -> None:
+    decorated = {}
+
+    def fake_gpu(fn=None, **kwargs):
+        def decorate(inner):
+            decorated["name"] = inner.__name__
+            decorated["kwargs"] = kwargs
+            setattr(inner, "_zero_gpu_wrapped", True)
+            return inner
+
+        if fn is not None:
+            return decorate(fn)
+        return decorate
+
+    monkeypatch.setitem(sys.modules, "spaces", SimpleNamespace(GPU=fake_gpu))
+    sys.modules.pop("backend.omnivoice_adapter", None)
+
+    module = importlib.import_module("backend.omnivoice_adapter")
+
+    assert decorated == {"name": "synthesize", "kwargs": {"duration": 300}}
+    assert getattr(module.OmniVoiceAdapter.synthesize, "_zero_gpu_wrapped", False) is True