fix(compressor): propagate api_mode and fix root logger calls

- Add api_mode to 4 update_model() call sites:
  - conversation_loop.py: long_context failover and probe stepping
  - agent_runtime_helpers.py: rollback restore (also saves compressor_api_mode)
  - chat_completion_helpers.py: fallback activation
- Fix 31 root-logger calls across 5 files (logging.warning/error/info
  -> logger.warning/error/info) to respect module-level log filtering

agent/model_metadata.py

@@ -641,7 +641,7 @@ def fetch_model_metadata(force_refresh: bool = False) -> Dict[str, Dict[str, Any
         return cache
 
     except Exception as e:
-        logging.warning(f"Failed to fetch model metadata from OpenRouter: {e}")
+        logger.warning(f"Failed to fetch model metadata from OpenRouter: {e}")
         return _model_metadata_cache or {}