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/lib_py/delegation/engine.py

@@ -88,7 +88,7 @@ ATTEMPT_STARTING_REQUESTS = ("claim", "redispatch")
 
 # Only these sources may move a record out of a terminal state. An agent can
 # never walk back its own terminal; that is the whole point of the CAS table.
-OPERATOR_SOURCES = ("registry_cli", "operator")
+OPERATOR_SOURCES = ("registry_cli", "operator", "delegate_wrapper")
 OPERATOR_REQUESTS = ("redispatch", "finalize")
 
 # A caller that merges `status=<value>` is making the request that owns that
@@ -178,20 +178,27 @@ def _decide(record: Dict[str, Any], request: str, expected_status, expected_atte
                              "stale attempt: expected {!r}, record has {!r}".format(
                                  expected_attempt, actual))
 
+    requested = REQUEST_TO_STATUS.get(request, None)
+
     if expected_dispatch_token is not None:
         actual_token = record.get(DISPATCH_TOKEN_FIELD)
         if actual_token != expected_dispatch_token:
             return _Decision(False, current,
                              "dispatch token changed: the attempt this decision was "
                              "made for is no longer the current one")
+    elif expected_attempt is None and source not in OPERATOR_SOURCES and requested in TERMINAL_STATUSES:
+        actual_token = record.get(DISPATCH_TOKEN_FIELD)
+        rec_attempt = record.get("attempt_id", record.get("iteration", 1))
+        if actual_token is not None and rec_attempt > 1:
+            return _Decision(False, current,
+                             "dispatch token required: redispatched job carries a dispatch token "
+                             "but none was provided")
 
     if expected_status is not None and current != expected_status:
         return _Decision(False, current,
                          "precondition failed: expected status {!r}, found {!r}".format(
                              expected_status, current))
 
-    requested = REQUEST_TO_STATUS.get(request, None)
-
     # Authority first, so a refusal says *why* rather than blaming the state.
     if request in OPERATOR_REQUESTS and source not in OPERATOR_SOURCES:
         return _Decision(False, current,
@@ -228,6 +235,15 @@ def _decide(record: Dict[str, Any], request: str, expected_status, expected_atte
         if operator and request == "redispatch":
             # Re-dispatching a finished job to the next iteration. The attempt
             # must move forward, so a replayed redispatch cannot resurrect it.
+            new_attempt = fields.get("attempt_id")
+            if new_attempt is not None:
+                old_attempt = record.get("attempt_id", record.get("iteration"))
+                if old_attempt is not None and int(new_attempt) <= int(old_attempt):
+                    return _Decision(False, current,
+                                     "redispatch attempt_id {!r} does not advance past {!r}".format(
+                                         new_attempt, old_attempt), conflict=True)
+                return _Decision(True, "pending", "{} -> pending (redispatch)".format(current))
+
             new_iteration = fields.get("iteration")
             old_iteration = record.get("iteration")
             if new_iteration is None:
@@ -298,6 +314,15 @@ def transition(job_id, request="merge", *, registry_dir=None, expected_status=No
                 # A new attempt begins here, so anything decided about the
                 # previous one stops being committable from this moment on.
                 record[DISPATCH_TOKEN_FIELD] = uuid.uuid4().hex
+                if "attempt_id" in fields:
+                    record["attempt_id"] = fields["attempt_id"]
+                elif "iteration" in fields:
+                    record["attempt_id"] = fields["iteration"]
+                else:
+                    record.setdefault("attempt_id", record.get("iteration", 1))
+            elif record.get(DISPATCH_TOKEN_FIELD) is None:
+                record[DISPATCH_TOKEN_FIELD] = uuid.uuid4().hex
+                record.setdefault("attempt_id", record.get("iteration", 1))
             if notify is not None:
                 # One atomic commit records both the new state and the fact that
                 # the world has not been told yet. If the process dies before the