Remove hardcoded token and require it from environment variables

src/config.py

@@ -26,7 +26,8 @@ class Config:
     MAX_OUTPUT_LENGTH = int(os.getenv("MAX_OUTPUT_LENGTH", 1024))
     TEMPERATURE = float(os.getenv("TEMPERATURE", 0.7))
     TOP_P = float(os.getenv("TOP_P", 0.95))
-    HUGGING_FACE_TOKEN = os.getenv("HUGGING_FACE_TOKEN", "")
+    # Token must be set in environment variables
+    HUGGING_FACE_TOKEN = os.getenv("HUGGING_FACE_TOKEN")
 
     # Database Settings
     DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///./code_review.db")
@@ -59,7 +60,7 @@ class Config:
         logger.info(f"DEBUG: {Config.DEBUG}")
 
         if not Config.HUGGING_FACE_TOKEN:
-            raise ValueError("HUGGING_FACE_TOKEN must be set to access Hugging Face gated models.")
+            raise ValueError("HUGGING_FACE_TOKEN must be set in environment variables to access Hugging Face models.")
         if Config.TEMPERATURE < 0 or Config.TEMPERATURE > 1:
             raise ValueError("TEMPERATURE must be between 0 and 1.")
         if Config.TOP_P < 0 or Config.TOP_P > 1: