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>

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:
-    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)
+def _kill_servers(box: Box) -> None:
     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