test(update): a retried owed restart now relaunches a paused manual gateway

The post-commit cell assumed a manual `gateway run` that died at boot leaves the retry nothing to
relaunch. The pre-swap pause records its argv, so the retry relaunches it on HEAD; the cell now
asserts that, keeping the invariant that the obligation discharges only once a gateway serves HEAD
(observed: PID 6 -> 1210, code_sha == HEAD). The operator-restart leg is gone: it would start a twin.

tests/e2e/core/upgrade/git/test_hostile_post.py

@@ -431,31 +431,21 @@ def test_gateway_that_cannot_reboot_is_an_owed_restart_not_a_failed_update(w):
             assert OWED_RESTART in G.output(status), \
                 f"a later command does not warn that a gateway restart is still owed:\n{diag}"
 
-            # The fault clears; the next plain update retries the owed restart. This gateway is a
-            # manual `gateway run` that died at boot: no supervisor and no live process, so the
-            # retry has nothing it can relaunch. It must still exit 0 and must NOT silently discharge
-            # the obligation (no gateway serves HEAD yet).
+            # The fault clears; the next plain update retries the owed restart. The gateway was a
+            # manual `gateway run` with no supervisor, but the pre-swap pause recorded its argv, so the
+            # retry relaunches it on HEAD. The obligation may discharge only because a gateway now
+            # serves HEAD, never while none does.
             _toggle(w, BREAK_GATEWAY, False)
             cp = _ns_update(host, w)
+            served = None
+            with contextlib.suppress(AssertionError):
+                served = H.wait_for(lambda: _serving(w, target), timeout=240, interval=1.0, what="a gateway on HEAD")
             status = _ns_cli(host, w, "status", timeout=300)
             diag = (_facts(w, cp, identify_after=_identify(w)) + w.diag(cp) + "\n--- gateway logs ---\n"
                     + _gateway_logs(w)[-6000:] + "\n--- sandbox ---\n" + host.ps_text()
                     + "\n--- hermes status ---\n" + G.output(status)[-3000:])
             assert cp.returncode == 0, f"the retrying update failed:\n{diag}"
-            assert OWED_RESTART in G.output(status), \
-                f"the retry discharged the owed restart while no gateway serves HEAD:\n{diag}"
-
-            # The operator restarts it (the remedy the warning names); once a gateway serves HEAD the
-            # obligation discharges and the warning goes away.
-            host.spawn([w.sb.hermes, "gateway", "run"], log=w.sb.root / "gateway-b2.log")
-            served = None
-            with contextlib.suppress(AssertionError):
-                served = H.wait_for(lambda: _serving(w, target), timeout=240, interval=1.0, what="a gateway on HEAD")
-            status = _ns_cli(host, w, "status", timeout=300)
-            diag = (_facts(w, cp, identify_after=_identify(w)) + "\n--- gateway logs ---\n"
-                    + _gateway_logs(w)[-6000:] + "\n--- sandbox ---\n" + host.ps_text()
-                    + "\n--- hermes status ---\n" + G.output(status)[-3000:])
-            assert served, f"premise: the restarted gateway never served {target[:12]}:\n{diag}"
+            assert served, f"the retry did not relaunch the paused gateway on {target[:12]}:\n{diag}"
             assert OWED_RESTART not in G.output(status), \
                 f"the owed-restart warning survived a gateway serving HEAD:\n{diag}"
         finally: