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.sh

@@ -2322,7 +2322,7 @@ delegate_publish_cmd() {
   pub_reg="${MAM_JOBS_DIR:-${WORKSPACE_ROOT:+$WORKSPACE_ROOT/.mam/jobs}}"
   pub_reg="${pub_reg:-.mam/jobs}"
   mkdir -p "$pub_reg" && pub_reg="$(cd -P "$pub_reg" && pwd -P)"
-  pub_logs="$(PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" "$py_bin" -c 'import os, sys; from lib_py.delegation.mqtt_common import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[1])))' "$pub_reg" 2>/dev/null || true)"
+  pub_logs="$(PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" "$py_bin" -c 'import os, sys; from lib_py.delegation.logroot import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[1])))' "$pub_reg" 2>/dev/null || true)"
   local -a argv=("$py_bin" "$pub_script" --registry-dir "$pub_reg" --job "$job_id")
   [ -n "$tok" ] && argv+=(--expect-dispatch-token "$tok")
   [ -n "$att" ] && argv+=(--attempt-id "$att")
@@ -2373,7 +2373,7 @@ except Exception:
 # closes it or another dispatch claims it. Lines are parsed as JSON, never
 # pattern-matched. rc 0 = recorded, 1 = not (yet).
 delegate_logs_dir() {
-  PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" "$(_delegate_py_bin)" -c 'import os, sys; from lib_py.delegation.mqtt_common import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[1])))' "$1" 2>/dev/null
+  PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" "$(_delegate_py_bin)" -c 'import os, sys; from lib_py.delegation.logroot import get_logs_dir; print(os.path.abspath(get_logs_dir(sys.argv[1])))' "$1" 2>/dev/null
 }
 
 delegate_started_recorded() {