fix log level error

app/config.py

@@ -73,6 +73,11 @@ class Settings(BaseSettings):
     rerank_provider: str = os.getenv("RERANK_PROVIDER", "") or llm_provider
     rerank_model: str = os.getenv("RERANK_MODEL", "") or llm_model
 
+    @field_validator("log_level")
+    @classmethod
+    def uppercase_log_level(cls, v: str) -> str:
+        return v.upper()
+
     @property
     def gemini_api_keys_list(self):
         return [k.strip() for k in self.gemini_api_keys.split(",") if k.strip()]