fix(gateway): launchd_stop uses bootout so KeepAlive doesn't respawn

launchd_stop() previously used `launchctl kill SIGTERM` which only
signals the process. Because the plist has KeepAlive.SuccessfulExit=false,
launchd immediately respawns the gateway — making `hermes gateway stop`
a no-op that prints '✓ Service stopped' while the service keeps running.

Switch to `launchctl bootout` which unloads the service definition so
KeepAlive can't trigger. The process exits and stays stopped until
`hermes gateway start` (which already handles re-bootstrapping unloaded
jobs via error codes 3/113).

Also adds _wait_for_gateway_exit() after bootout to ensure the process
is fully gone before returning, and tolerates 'already unloaded' errors.

Fixes: .env changes not taking effect after gateway stop+restart on macOS.
The root cause was that stop didn't actually stop — the respawned process
loaded the old env before the user's restart command ran.

hermes_cli/gateway.py

@@ -1209,7 +1209,19 @@ def launchd_start():
 
 def launchd_stop():
     label = get_launchd_label()
-    subprocess.run(["launchctl", "kill", "SIGTERM", f"{_launchd_domain()}/{label}"], check=True, timeout=30)
+    target = f"{_launchd_domain()}/{label}"
+    # bootout unloads the service definition so KeepAlive doesn't respawn
+    # the process.  A plain `kill SIGTERM` only signals the process — launchd
+    # immediately restarts it because KeepAlive.SuccessfulExit = false.
+    # `hermes gateway start` re-bootstraps when it detects the job is unloaded.
+    try:
+        subprocess.run(["launchctl", "bootout", target], check=True, timeout=90)
+    except subprocess.CalledProcessError as e:
+        if e.returncode in (3, 113):
+            pass  # Already unloaded — nothing to stop.
+        else:
+            raise
+    _wait_for_gateway_exit(timeout=10.0, force_after=5.0)
     print("✓ Service stopped")
 
 def _wait_for_gateway_exit(timeout: float = 10.0, force_after: float = 5.0):

tests/hermes_cli/test_gateway_service.py

@@ -234,6 +234,63 @@ class TestLaunchdServiceRecovery:
             ["launchctl", "kickstart", target],
         ]
 
+    def test_launchd_stop_uses_bootout_not_kill(self, monkeypatch):
+        """launchd_stop must bootout the service so KeepAlive doesn't respawn it."""
+        label = gateway_cli.get_launchd_label()
+        domain = gateway_cli._launchd_domain()
+        target = f"{domain}/{label}"
+
+        calls = []
+
+        def fake_run(cmd, check=False, **kwargs):
+            calls.append(cmd)
+            return SimpleNamespace(returncode=0, stdout="", stderr="")
+
+        monkeypatch.setattr(gateway_cli.subprocess, "run", fake_run)
+        monkeypatch.setattr(gateway_cli, "_wait_for_gateway_exit", lambda **kw: None)
+
+        gateway_cli.launchd_stop()
+
+        assert calls == [["launchctl", "bootout", target]]
+
+    def test_launchd_stop_tolerates_already_unloaded(self, monkeypatch, capsys):
+        """launchd_stop silently handles exit codes 3/113 (job not loaded)."""
+        label = gateway_cli.get_launchd_label()
+        domain = gateway_cli._launchd_domain()
+        target = f"{domain}/{label}"
+
+        def fake_run(cmd, check=False, **kwargs):
+            if "bootout" in cmd:
+                raise gateway_cli.subprocess.CalledProcessError(3, cmd, stderr="Could not find service")
+            return SimpleNamespace(returncode=0, stdout="", stderr="")
+
+        monkeypatch.setattr(gateway_cli.subprocess, "run", fake_run)
+        monkeypatch.setattr(gateway_cli, "_wait_for_gateway_exit", lambda **kw: None)
+
+        # Should not raise — exit code 3 means already unloaded
+        gateway_cli.launchd_stop()
+
+        output = capsys.readouterr().out
+        assert "stopped" in output.lower()
+
+    def test_launchd_stop_waits_for_process_exit(self, monkeypatch):
+        """launchd_stop calls _wait_for_gateway_exit after bootout."""
+        wait_called = []
+
+        def fake_run(cmd, check=False, **kwargs):
+            return SimpleNamespace(returncode=0, stdout="", stderr="")
+
+        def fake_wait(**kwargs):
+            wait_called.append(kwargs)
+
+        monkeypatch.setattr(gateway_cli.subprocess, "run", fake_run)
+        monkeypatch.setattr(gateway_cli, "_wait_for_gateway_exit", fake_wait)
+
+        gateway_cli.launchd_stop()
+
+        assert len(wait_called) == 1
+        assert wait_called[0] == {"timeout": 10.0, "force_after": 5.0}
+
     def test_launchd_status_reports_local_stale_plist_when_unloaded(self, tmp_path, monkeypatch, capsys):
         plist_path = tmp_path / "ai.hermes.gateway.plist"
         plist_path.write_text("<plist>old content</plist>", encoding="utf-8")