fix(issue-50): the loop path waits by the registry on its pending record (review F1-F3)

F1: from phase two on, the loop's `_registry_wait` ran before the record was
reset to pending, so the waiter held a terminal record: the engine refused its
dispatch_wait_at merge and other waiters never saw it in the FIFO. The wait
(and the idle wait after it) now follows the `--status pending` update; s1
pins the order and u3c shows why a terminal self record cannot signal.
F2: the real-herdr box teardown survives a hung stop/delete, kills a server
bootstrapped by a late client call, and asserts the server and HOME are gone.
F3: the delegate-job SKILL.md exit 5 row names the registry wait.
Also drops the dead loop in s1.

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

.agents/skills/multi-agent-mux-delegate-job/SKILL.md

@@ -104,7 +104,7 @@ Under fail-closed operation (`MAM_DELEGATE_FAIL_CLOSED=1`, default), the CLI ret
 | `2` | Timeout | `error` (`deadline_timeout`) | Subscriber idle timeout (K x N without an event; the total budget is the wall-clock row below). **R1 liveness grace (Issue #18)**: after the subscriber idles out the wrapper keeps re-observing the disk while the job's events.log shows an event at most K x N (`--idle-timeout`) old - the automatic heartbeat counts - up to the wall-clock `--timeout`. herdr status and the pane are logged as a diagnostic only. |
 | `2` | Wall clock | `error` (`wall_clock_timeout`) | The budget (`--timeout`) ran out, events or not (Issue #33; was `deadline_timeout` before v4.8.0). |
 | `3` | Broker Error | `error` (`wall_clock_timeout` once the budget is spent, else `deadline_timeout`) | Broker unavailable (`MQTT_BROKER_UNAVAILABLE`) and terminal status not found on disk during deadline. |
-| `5` | Session Busy | `cancelled` (`session_busy`) | Precondition failed / `session_busy`: Preflight check (`preflight_agent`) or TUI idle handshake wait failed (prompt never delivered, retryable). |
+| `5` | Session Busy | `cancelled` (`session_busy`) | Precondition failed / `session_busy`: Preflight check (`preflight_agent`) or TUI idle handshake wait failed, or the session's open jobs in the registry did not end within `MAM_DISPATCH_WAIT_S` (Issue #50) (prompt never delivered, retryable). |
 
 In all execution paths, the final line of standard output prints the persistent audit log directory path (`<logs_root>/<job_id>`), fulfilling the parsing contract for orchestrator runners.
 

.agents/skills/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -518,7 +518,19 @@ EOF
         exit 5
       fi
 
-      # Registry wait (Issue #50), then idle wait
+      # Update job details in registry
+      "$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" update \
+          --job "$JOB_ID" \
+          --agent-session "$current_session" \
+          --prompt-file "$job_dir/prompt.md" \
+          --iteration "$iteration" \
+          --attempt-id "$attempt" \
+          --role "$display_role" \
+          --status "pending"
+
+      # Registry wait (Issue #50), then idle wait - on the record just reset to
+      # pending for this phase, so the waiter's signal is written and other
+      # waiters see this job in the FIFO (review F1)
       local cur_agent="$AGENT"
       [ "$_phase" = "reviewer" ] && cur_agent="$REVIEWER"
       if [ "$cur_agent" != "human" ] && ! _is_remote "$current_session"; then
@@ -534,16 +546,6 @@ EOF
         fi
       fi
 
-      # Update job details in registry
-      "$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" update \
-          --job "$JOB_ID" \
-          --agent-session "$current_session" \
-          --prompt-file "$job_dir/prompt.md" \
-          --iteration "$iteration" \
-          --attempt-id "$attempt" \
-          --role "$display_role" \
-          --status "pending"
-
       local _disp_tok=""
       _disp_tok="$("$PY" -c "import json, os; p=os.path.join('$REGISTRY_DIR', '$JOB_ID.json'); print(json.load(open(p)).get('dispatch_token','') or '') if os.path.exists(p) else print('')" 2>/dev/null || true)"
 

tests/test_issue50_dispatch.py

@@ -185,6 +185,21 @@ def test_u3_the_waiter_signals_on_its_own_record(tmp_path):
     assert me in {j for _c, j, _s in live}
 
 
+def test_u3c_a_terminal_self_record_cannot_carry_the_signal(tmp_path):
+    # why the loop path resets its record to pending before it waits (s1):
+    # the engine refuses a merge into a terminal record, so the waiter would
+    # stay invisible to every other waiter's FIFO
+    a = _register(tmp_path, status="running")
+    _event(tmp_path, a, time.time())
+    me = _register(tmp_path, status="completed")
+    assert decide.wait_open_jobs(_ns(tmp_path, me, wait_s=1)) == f"busy {a}"
+    after = json.loads((tmp_path / f"{me}.json").read_text())
+    assert after["status"] == "completed" and "dispatch_wait_at" not in after
+    later = _register(tmp_path)
+    live, _stale = decide.open_jobs(str(tmp_path), "herdr:s", later)
+    assert me not in {j for _c, j, _s in live}
+
+
 def test_u3b_the_signal_is_a_registry_merge(tmp_path, monkeypatch):
     me = _register(tmp_path)
     seen = {}
@@ -262,12 +277,14 @@ def test_s1_both_dispatch_paths_wait_by_the_registry_before_the_idle_wait():
     src = WRAPPER.read_text()
     assert src.count('_registry_wait "$JOB_ID" "$AGENT_SESSION"') == 1
     assert src.count('_registry_wait "$JOB_ID" "$current_session"') == 1
-    for block in src.split("wait_for_agent_idle ")[1:]:
-        pass
     direct = src.index('_registry_wait "$JOB_ID" "$AGENT_SESSION"')
     assert direct < src.index('wait_for_agent_idle "$AGENT_SESSION"')
     loop = src.index('_registry_wait "$JOB_ID" "$current_session"')
     assert loop < src.index('wait_for_agent_idle "$current_session"')
+    # the loop path waits on the record already reset to pending for this
+    # phase (review F1): a terminal self record cannot carry the signal (u3c)
+    assert src.count('--status "pending"') == 1
+    assert src.index('--status "pending"') < loop
     body = src.split("_registry_wait() {")[1].split("\n}\n")[0]
     assert "wait-open-jobs" in body and 'finalize_unfinished "$job_id" "error" "$SUB_RC_ERROR" "registry_wait"' in body
     assert "exit 5" in body and "mam_int_knob MAM_DISPATCH_WAIT_S 600 0" in body

tests/test_issue50_dispatch_herdr.py

@@ -209,24 +209,38 @@ def _start_pane(box: Box, name=SESSION, cwd=None) -> None:
     assert box.agent_status(name) == "idle", box.herdr("agent", "list").stdout
 
 
-def _teardown(box: Box) -> None:
+def _kill_servers(box: Box) -> None:
-    if os.environ.get("MAM_T50_KEEP_BOX"):   # debugging aid: leave the box and the server in place
-        print("KEEP_BOX", box.home, box.sess)
-        return
-    for sub in (("session", "stop", box.sess), ("session", "delete", box.sess)):
-        subprocess.run([HERDR, *sub], capture_output=True, text=True, env={"HOME": str(box.home), "PATH": os.environ["PATH"]},
-                       timeout=30)
-        time.sleep(0.5)
     for pid in box.server_pids():
         try:
             os.kill(pid, signal.SIGKILL)
         except OSError:
             pass
+
+
+def _teardown(box: Box) -> None:
+    if os.environ.get("MAM_T50_KEEP_BOX"):   # debugging aid: leave the box and the server in place
+        print("KEEP_BOX", box.home, box.sess)
+        return
+    for sub in (("session", "stop", box.sess), ("session", "delete", box.sess)):
+        try:
+            subprocess.run([HERDR, *sub], capture_output=True, text=True,
+                           env={"HOME": str(box.home), "PATH": os.environ["PATH"]}, timeout=30)
+        except subprocess.TimeoutExpired:
+            pass                             # the kill below is what must run (review F2)
+        time.sleep(0.5)
+    _kill_servers(box)
     shutil.rmtree(box.home, ignore_errors=True)
     # herdr writes its agent-detection state under $HOME/.local/state a moment
-    # after the server is gone: sweep once more
+    # after the server is gone, and a late client call can bootstrap a new
+    # server: sweep and kill once more, then prove the server is gone
     time.sleep(1)
+    _kill_servers(box)
     shutil.rmtree(box.home, ignore_errors=True)
+    deadline = time.time() + 5
+    while box.server_pids() and time.time() < deadline:
+        time.sleep(0.2)
+    assert not box.server_pids(), f"a server of {box.sess} survived teardown"
+    assert not box.home.exists(), f"{box.home} survived teardown"
 
 
 @pytest.fixture