fix check cache

app.py

@@ -679,14 +679,14 @@ def generate_tts():
         model_a = candidate_models[i]
         audio_a_path = find_cached_audio(str(model_a.id), text, reference_audio_path)
         app.logger.warning(f"checking {audio_a_path}")
-        if not os.path.exists(audio_a_path) or has_long_silence(audio_a_path):
+        if not audio_a_path or has_long_silence(audio_a_path):
             continue
         # 检测到a模型音频有效，继续检测b模型
         for j in range(i + 1, len(candidate_models)):
             model_b = candidate_models[j]
             audio_b_path = find_cached_audio(str(model_b.id), text, reference_audio_path)
             app.logger.warning(f"checking {audio_b_path}")
-            if not os.path.exists(audio_b_path) or has_long_silence(audio_b_path):
+            if not audio_b_path or has_long_silence(audio_b_path):
                 continue
             valid_pairs.append((model_a, audio_a_path, model_b, audio_b_path))
             app.logger.warning(f"Found valid model pair: {model_a.name} and {model_b.name} for text '{text[:50]}...'")