Stabilize core correctness and sync project plan state

src/atocore/observability/logger.py

@@ -2,10 +2,9 @@
 
 import logging
 
+import atocore.config as _config
 import structlog
 
-from atocore.config import settings
-
 _LOG_LEVELS = {
     "DEBUG": logging.DEBUG,
     "INFO": logging.INFO,
@@ -16,7 +15,7 @@ _LOG_LEVELS = {
 
 def setup_logging() -> None:
     """Configure structlog with JSON output."""
-    log_level = "DEBUG" if settings.debug else "INFO"
+    log_level = "DEBUG" if _config.settings.debug else "INFO"
 
     structlog.configure(
         processors=[