fix(issue-6): fail-closed registry timeout and TUI turn handshake

- Introduce finalize_unfinished in multi-agent-mux-delegate-job for fail-closed atomic transitions
- Enforce CAS dispatch_token and attempt_id pinning across engine, CLI, and lifecycle scripts
- Integrate Herdr wait_for_agent_idle turn handshake to prevent prompt loss and race conditions
- Resolve bash 3.2 set -u empty array expansion compatibility in lib.sh
- Preserve Issue #5 R2 contract in CAS transition engine (engine.py, publish_event.py, service.py)
- Add comprehensive regression suites (test_issue6_fail_closed.py, test_issue6_turn_handshake.py)
- Bump lockstep framework and skills to v4.4.1 across lib.sh, eager.py, VERSIONS.md, 8 SKILL.md
- Synchronize documentation (IMPROVEMENTS.md, MESSAGING.md, state-transitions.md, task.md, phase5-e2e.md)
- Unanimous PASS achieved across 4 reviewer team leaders (Claude, Codex, OpenCode, Grok)

Closes #6

.agents/skills/multi-agent-mux-create/scripts/create_session.sh

@@ -344,6 +344,29 @@ if [ -n "$SUBMIT_JOB_PROMPT" ]; then
   agent_session="herdr:$SESSION_NAME"
   DELEGATE_JOB_ID=$(delegate_submit_job "$SUBMIT_JOB_PROMPT" "$delegate_agent" "$agent_session")
   echo "Submitted delegated job: $DELEGATE_JOB_ID"
+  DELEGATE_JOB_TOKEN=""
+  DELEGATE_JOB_ATTEMPT=""
+  if [ -n "$DELEGATE_JOB_ID" ]; then
+    local_info=$(python3 -c "
+import sys, json, os
+jid = '$DELEGATE_JOB_ID'
+reg_dir = os.environ.get('MAM_JOBS_DIR', '.mam/jobs')
+p = os.path.join(reg_dir, f'{jid}.json')
+if os.path.exists(p):
+    try:
+        with open(p) as f:
+            d = json.load(f)
+            tok = d.get('dispatch_token', '')
+            att = d.get('attempt_id', d.get('iteration', 1))
+            print(f'{tok} {att}')
+    except Exception:
+        pass
+" 2>/dev/null || true)
+    if [ -n "$local_info" ]; then
+      DELEGATE_JOB_TOKEN=$(echo "$local_info" | awk '{print $1}')
+      DELEGATE_JOB_ATTEMPT=$(echo "$local_info" | awk '{print $2}')
+    fi
+  fi
 fi
 
 if [ ! -f "$AGENT_SESSIONS_YAML" ]; then
@@ -494,11 +517,11 @@ Task: $SUBMIT_JOB_PROMPT"
   rc=0
   inject_instructions "$SESSION_NAME" "$instructions" "$DELEGATE_JOB_ID" || rc=$?
   if [ "$rc" -ne 0 ]; then
-    delegate_publish_event "$DELEGATE_JOB_ID" error "instruction injection failed (prompt-lock, rc=$rc)"
+    delegate_publish_event "$DELEGATE_JOB_ID" error "instruction injection failed (prompt-lock, rc=$rc)" "$DELEGATE_JOB_TOKEN" "$DELEGATE_JOB_ATTEMPT"
     exit 1
   fi
   
-  delegate_publish_event "$DELEGATE_JOB_ID" started "multi-agent-mux session created and instructions injected"
+  delegate_publish_event "$DELEGATE_JOB_ID" started "multi-agent-mux session created and instructions injected" "$DELEGATE_JOB_TOKEN" "$DELEGATE_JOB_ATTEMPT"
   # Trigger immediate priority reconcile cycle asynchronously
   (bash "$WORKSPACE/.agents/skills/multi-agent-mux-monitor/scripts/reconcile.sh" --once >/dev/null 2>&1 &) || true
   WD_PID=$(start_watchdog "$DELEGATE_JOB_ID" "$WORKSPACE")