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/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -92,7 +92,7 @@ _abs_registry_dir() {
 # #57), pinned into the injected commands so an agent publishing from another
 # cwd does not fall back to its own default.
 _logs_dir_abs() {
-  "$PY" -c 'import os, sys; sys.path.insert(0, sys.argv[1]); from lib_py.delegation.mqtt_common import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[2])))' "$SCRIPT_DIR/.." "$REGISTRY_DIR"
+  "$PY" -c 'import os, sys; sys.path.insert(0, sys.argv[1]); from lib_py.delegation.logroot import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[2])))' "$SCRIPT_DIR/.." "$REGISTRY_DIR"
 }
 
 # Issue #17 item 4: the wrapper's decisions are lib_py/delegation/wrapper.py;