fix(issue-14): keep the idle-timeout working grace alive on the pane busy token

The R1 grace after a subscriber idle timeout only asked herdr whether the
agent was still `working`. herdr never reports that for codex, so a codex
review longer than the idle timeout was closed as deadline_timeout mid-turn
and its eventual `completed` refused - the same status blindness behind the
agent_blocked misjudgement. `_agent_still_working` now also accepts the pane's
own busy token, the evidence send_keys_safe already uses to confirm delivery.

Adds a wrapper test where a codex-like agent (idle per herdr, busy per pane)
idles out the subscriber and completes out of band afterwards.

Refs #14

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

tests/test_issue14_delivery_ack.py

@@ -240,3 +240,65 @@ def test_wrapper_honours_registry_ack_over_unconfirmed_inject(tmp_path, mock_her
         assert "agent_blocked" not in events_log.read_text(), events_log.read_text()
     job_data = json.loads((reg_dir / f"{jid}.json").read_text())
     assert job_data.get("status") != "pending"
+
+
+# ---------------------------------------------------------------------------
+# wrapper: idle-timeout grace (R1) must see a working codex through the pane
+# ---------------------------------------------------------------------------
+def test_wrapper_idle_timeout_grace_accepts_pane_busy_token(tmp_path, mock_herdr):
+    """herdr keeps reporting `idle` for a codex-like agent that is visibly
+    working (busy token in the pane). When the subscriber idles out, the
+    wrapper must keep waiting for the on-disk result instead of closing the
+    job as deadline_timeout mid-turn; the agent then completes out of band."""
+    reg_dir = tmp_path / "jobs"
+    reg_dir.mkdir(parents=True, exist_ok=True)
+
+    state_file = Path(mock_herdr)
+    state = json.loads(state_file.read_text())
+    # `timeout` from agent prompt keeps agent_status idle; the mock appends the
+    # busy token to the pane on submission, exactly like a codex turn.
+    state["agents"]["slow-codex"] = {
+        "agent": "codex",
+        "agent_status": "idle",
+        "prompt_wait_result": "timeout",
+        "buffer": "Ready",
+    }
+    state_file.write_text(json.dumps(state, indent=2))
+
+    env = _base_env(tmp_path, {"SKS_IDLE_TIMEOUT_MS": "500", "SKS_DELIVERY_GRACE_S": "5"})
+    proc = subprocess.Popen(
+        [
+            "bash", str(WRAPPER), "submit",
+            "--agent", "codex",
+            "--agent-session", "herdr:slow-codex",
+            "--prompt", "issue 14 idle grace",
+            "--registry-dir", str(reg_dir),
+            "--workdir", str(tmp_path),
+            "--timeout", "40",
+            "--idle-timeout", "3",
+        ],
+        cwd=str(tmp_path), env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True,
+    )
+
+    jid = ""
+    for _ in range(100):
+        job_files = list(reg_dir.glob("*.json"))
+        if job_files:
+            jid = job_files[0].stem
+            break
+        time.sleep(0.1)
+    assert jid, "job was not registered"
+
+    # Well past the 3 s idle timeout, the agent finishes.
+    time.sleep(14)
+    done = subprocess.run(
+        [sys.executable, str(REGISTRY_PY), "--registry-dir", str(reg_dir),
+         "update", "--job", jid, "--status", "completed"],
+        capture_output=True, text=True, cwd=str(tmp_path), env=env,
+    )
+    assert done.returncode == 0, done.stderr
+
+    stdout, stderr = proc.communicate(timeout=90)
+    job_data = json.loads((reg_dir / f"{jid}.json").read_text())
+    assert job_data.get("status") == "completed", f"status={job_data.get('status')}\n{stdout}\n{stderr}"
+    assert proc.returncode == 0, f"expected rc=0 after the working grace, got {proc.returncode}\n{stdout}\n{stderr}"