fix(delegation): the path rules live in a stdlib-only module; the package imports without paho (Issue #57, Mac F1)

control_plane and status.sh imported sibling_logs_dir from mqtt_common,
which imports paho at module level, so create/resume's binding and status
died on an interpreter without paho-mqtt (_delegate_py_bin's last fallback
is the PATH's python3). The registry/audit-log path rules move to
lib_py/delegation/logroot.py (standard library only) and mqtt_common
re-exports them. The package's own import chain also reached paho through
service -> publish_event -> publisher, so mqtt_common and publisher import
paho tolerantly and make_client() refuses with a clear error when a broker
is actually needed. control_plane, status.sh, lib.sh's delegate_publish_cmd
and delegate_logs_dir, and the wrapper's _logs_dir_abs import from logroot.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

.agents/skills/lib_py/delegation/publisher.py

@@ -14,7 +14,10 @@ import logging
 import time
 from typing import Any, Optional, Tuple
 
-import paho.mqtt.client as mqtt
+try:
+    import paho.mqtt.client as mqtt
+except ImportError:  # importable without a broker library; mqtt_common.make_client() refuses to connect
+    mqtt = None
 
 from lib_py.delegation import mqtt_common