fix(logging): resolve logging_compat keyword arg conflicts

- Fix logging_compat._log() to handle extra keyword arguments properly
- Update config.py, main.py, and test_bans.py for compatibility
- Update Tasks.md and runner.csx

backend/app/utils/logging_compat.py

@@ -17,10 +17,17 @@ class _CompatLogger:
     def __init__(self, logger: logging.Logger) -> None:
         self._logger = logger
 
+    _STDLIB_LOG_KWARGS = frozenset(("exc_info", "extra", "stack_info", "stacklevel"))
+
     def _log(self, level: int, event: str, **kwargs: Any) -> None:
-        exc_info = kwargs.pop("exc_info", None)
-        extra = kwargs if kwargs else None
-        self._logger.log(level, event, exc_info=exc_info, extra=extra)
+        stdlib_kwargs: dict[str, Any] = {}
+        for k in self._STDLIB_LOG_KWARGS:
+            v = kwargs.pop(k, None)
+            if v is not None:
+                stdlib_kwargs[k] = v
+        if kwargs:
+            stdlib_kwargs["extra"] = kwargs
+        self._logger.log(level, event, **stdlib_kwargs)
 
     def debug(self, event: str, **kwargs: Any) -> None:
         self._log(logging.DEBUG, event, **kwargs)