feat: Switch to Dolphin Mistral 24B (free model)

app.py

@@ -27,7 +27,7 @@ CONFIG = {
     'openrouter_key': os.getenv('OPENROUTER_API_KEY', ''),
     'whisper_model': os.getenv('WHISPER_MODEL', 'base'),
     'language': os.getenv('LANGUAGE', 'en'),
-    'llm_model': os.getenv('LLM_MODEL', 'anthropic/claude-sonnet-4-20250514'),
+    'llm_model': os.getenv('LLM_MODEL', 'cognitivecomputations/dolphin-mistral-24b-venice-edition:free'),
     'max_tokens': int(os.getenv('MAX_TOKENS', '4096')),
     'temperature': float(os.getenv('TEMPERATURE', '1.0'))
 }