refactor: Update GROQ_TOPIC_MODEL to the latest production version and adjust fallback models in TopicService for improved model selection and stability.

config.py

@@ -43,7 +43,7 @@ GROQ_TTS_FORMAT = "wav"
 GROQ_CHAT_MODEL = "llama3-70b-8192"
 
 # **Topic Extraction Model**
-GROQ_TOPIC_MODEL = "llama3-70b-8192"  # Using same model as chat for consistency
+GROQ_TOPIC_MODEL = "llama-3.3-70b-versatile"  # Latest production model, fallback: "llama3-70b-8192"
 
 # ============ SUPABASE ============
 SUPABASE_URL = os.getenv("SUPABASE_URL", "")
@@ -90,6 +90,7 @@ logger.info(f"  HF Label Model  : {HUGGINGFACE_LABEL_MODEL_ID}")
 logger.info(f"  GROQ STT Model  : {GROQ_STT_MODEL}")
 logger.info(f"  GROQ TTS Model  : {GROQ_TTS_MODEL}")
 logger.info(f"  GROQ Chat Model : {GROQ_CHAT_MODEL}")
+logger.info(f"  GROQ Topic Model: {GROQ_TOPIC_MODEL}")
 logger.info(f"  Google API Key  : {'✓ Configured' if GOOGLE_API_KEY else '✗ Not configured'}")
 logger.info(f"  Supabase URL    : {'✓ Configured' if SUPABASE_URL else '✗ Not configured'}")
 logger.info("="*60)

services/topic_service.py

@@ -22,14 +22,13 @@ class TopicService:
     
     def __init__(self):
         self.llm = None
-        # Use valid Groq model - defaults from config, fallback to common models
+        # Use valid Groq model - defaults from config, fallback to stable model
         self.model_name = GROQ_TOPIC_MODEL if GROQ_TOPIC_MODEL else "llama3-70b-8192"
         # Fallback models to try if primary fails (using current/available Groq models)
         self.fallback_models = [
-            "llama3-70b-8192",
-            "llama-3.1-8b-instant",
-            "mixtral-8x7b-32768",
-            "gemma2-9b-it"  # Alternative smaller model
+            "llama3-70b-8192",  # Stable production model (same as chat)
+            "llama-3.1-8b-instant",  # Faster, smaller alternative
+            "openai/gpt-oss-20b"  # Alternative OpenAI OSS model
         ]
         self.initialized = False