fix(k1): settle same-process standby checkpoint

tests/test_xgrids_active_acquisition_checkpoint_integration.py

@@ -455,11 +455,17 @@ def test_repeated_reset_reopen_fresh_ready_ceases_old_active_checkpoint(
     assert service._active_acquisition_checkpoint_trust == "trusted"  # noqa: SLF001
 
 
-def test_restart_ready_after_dispatched_stop_ceases_active_checkpoint(
+@pytest.mark.parametrize(
+    "same_process",
+    (False, True),
+    ids=("process-restart", "same-process-new-control-epoch"),
+)
+def test_ready_after_dispatched_stop_ceases_active_checkpoint(
     tmp_path: Path,
     monkeypatch: pytest.MonkeyPatch,
+    same_process: bool,
 ) -> None:
-    """Fresh READY settles a dispatched STOP whose outcome crossed restart."""
+    """Fresh READY settles a dispatched STOP across either recovery boundary."""
 
     service = _service(tmp_path, monkeypatch)
     original = _connection(
@@ -509,9 +515,10 @@ def test_restart_ready_after_dispatched_stop_ceases_active_checkpoint(
             observed_at_utc="2026-08-13T12:01:01.000Z",
         ),
     )
-    service._snapshot_runtime_id = (  # noqa: SLF001
-        "snapshot-runtime-checkpoint-dispatched-stop-successor"
-    )
+    if not same_process:
+        service._snapshot_runtime_id = (  # noqa: SLF001
+            "snapshot-runtime-checkpoint-dispatched-stop-successor"
+        )
     restarted = _connection(
         control_session_id="checkpoint-dispatched-stop-restarted-control",
         host_path_epoch=2,
@@ -561,6 +568,7 @@ def test_restart_ready_after_dispatched_stop_ceases_active_checkpoint(
         lambda: None,
     )
 
+    settle_checkpoint = service._settle_restart_checkpoint_after_verified_standby  # noqa: SLF001
     monkeypatch.setattr(
         service,
         "_settle_restart_checkpoint_after_verified_standby",
@@ -583,10 +591,23 @@ def test_restart_ready_after_dispatched_stop_ceases_active_checkpoint(
     assert checkpoint is not None
     assert checkpoint.state == "active"
 
-    # Simulate the exact live process boundary: the physical ledger fsync is
-    # durable, while checkpoint cessation did not commit in the prior process.
-    restarted_service = _service(tmp_path, monkeypatch)
-    assert restarted_service._active_acquisition_checkpoint_reason is None  # noqa: SLF001
+    # The physical ledger fsync is durable while checkpoint cessation did not
+    # commit. Recovery may happen after a process restart or, as observed in
+    # production, later in the same process under a fresh control/path epoch.
+    if same_process:
+        monkeypatch.setattr(
+            service,
+            "_settle_restart_checkpoint_after_verified_standby",
+            settle_checkpoint,
+        )
+        token = service._validate_active_acquisition_checkpoint_lineage()  # noqa: SLF001
+        assert token is not None
+        assert service._settle_durable_prepared_stop_standby_checkpoint(  # noqa: SLF001
+            token
+        ), service._active_acquisition_checkpoint_reason  # noqa: SLF001
+    else:
+        restarted_service = _service(tmp_path, monkeypatch)
+        assert restarted_service._active_acquisition_checkpoint_reason is None  # noqa: SLF001
     checkpoint = ActiveAcquisitionRecoveryCheckpointStore(tmp_path).snapshot().checkpoint
     assert checkpoint is not None
     assert checkpoint.state == "ceased"

tests/test_xgrids_active_acquisition_recovery_checkpoint.py

@@ -1312,6 +1312,7 @@ def test_cease_active_reconciled_standby_rejects_inexact_restart_proofs(
         replace(
             status.binding,
             runtime_instance_id=binding.runtime_instance_id,
+            host_path_epoch=binding.host_path_epoch,
         ),
         replace(
             status.binding,