fix(delegation): audit-log root follows the registry (Issue #57)

get_logs_dir(registry_dir) resolves the audit-log root as the
delegate_job_logs next to the registry in use when DELEGATE_JOB_LOGS_DIR
is not set; sibling_logs_dir() is the pure sibling rule. Every writer and
reader that knows its registry (registry, engine, publish_event, remote,
job_subscriber, reconcile.sh, the loop runner's fingerprint exclusion)
passes that root instead of falling back to the workspace default.

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

.agents/skills/multi-agent-mux-monitor/scripts/reconcile.sh

@@ -272,7 +272,7 @@ def on_message(_client, _userdata, msg):
             "topic": msg.topic,
             "timestamp": payload.get("timestamp"),
             "detail": payload.get("detail", ""),
-        })
+        }, logs_dir=mqtt_common.get_logs_dir(registry_dir))
         
         print(f"MQTT Monitor: recorded event {event} for job {jid} (seq={seq})", flush=True)