Rename shared/logging/ to shared/log_config/ to avoid stdlib shadow

shared/logging/ shadows Python's stdlib logging module, causing a
circular import when any code does `import logging`. This breaks
both the entrypoint Redis flush and Hypercorn app loading.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

log_config/__init__.py

@@ -0,0 +1,3 @@
+from .setup import configure_logging, get_logger
+
+__all__ = ["configure_logging", "get_logger"]