[F034] orchestrator: re-stamp respawn last_check at restore

_pm_made_rule_following_retry bounds its tracing_gap audit lookup with
since = record.get('last_check'). A stale persisted last_check from before
the restart matched pre-restart tracing_gap rows, falsely resetting the
breaker on the very first post-restart spawn — exactly when a fresh strike
count should be evaluating current state.

_partition_respawn_rows now re-stamps last_check to the restore time on
every restorable entry, bounding the lookup to post-restart gaps only.

roboco/runtime/orchestrator.py

@@ -4999,7 +4999,9 @@ class AgentOrchestrator:
 
     @staticmethod
     def _partition_respawn_rows(
-        rows: "Iterable[Any]", status_by_id: dict[Any, Any]
+        rows: "Iterable[Any]",
+        status_by_id: dict[Any, Any],
+        now: datetime | None = None,
     ) -> tuple[dict[tuple[str, str], dict[str, Any]], list[tuple[str, Any]]]:
         """Split persisted respawn rows into (restorable entries, stale keys).
 
@@ -5008,9 +5010,17 @@ class AgentOrchestrator:
         against a fixed/deleted task. Restorable entries are keyed
         ``(agent_slug, str(task_id))`` to match the in-memory dict; stale keys
         carry the raw ``task_id`` for deletion.
+
+        F034: ``last_check`` is re-stamped to ``now`` (the restore time) on
+        every restorable entry. ``_pm_made_rule_following_retry`` reads
+        ``since = record.get("last_check")`` to bound its tracing_gap audit
+        lookup; a stale pre-restart ``last_check`` would match a pre-restart
+        tracing_gap row and falsely reset the breaker on the first post-restart
+        spawn. Re-stamping bounds the lookup to post-restart gaps only.
         """
         from roboco.models.base import TaskStatus
 
+        restore_now = now or datetime.now(UTC)
         terminal = {TaskStatus.COMPLETED.value, TaskStatus.CANCELLED.value}
         restored: dict[tuple[str, str], dict[str, Any]] = {}
         stale: list[tuple[str, Any]] = []
@@ -5023,7 +5033,7 @@ class AgentOrchestrator:
             restored[(r.agent_slug, str(r.task_id))] = {
                 "count": r.count,
                 "last_status": r.last_status,
-                "last_check": r.last_check,
+                "last_check": restore_now,
                 "tracing_resets": r.tracing_resets,
                 "notified": r.notified,
             }

tests/unit/runtime/test_respawn_persistence.py

@@ -80,6 +80,26 @@ def test_partition_drops_terminal_and_missing_rows() -> None:
     }
 
 
+def test_partition_restamps_last_check_to_now_to_avoid_stale_tracing_gap() -> None:
+    # F034: a persisted last_check from BEFORE the restart would make the first
+    # post-restart ``_pm_made_rule_following_retry`` audit lookup
+    # (``since = record.get("last_check")``) match a PRE-restart tracing_gap
+    # row, falsely resetting the breaker on the very first post-restart spawn —
+    # exactly when a fresh strike count should be evaluating current state.
+    # Restore must re-stamp last_check to the restore time so only post-restart
+    # tracing gaps can reset the counter.
+    tid = uuid4()
+    stale_check = datetime(2026, 6, 20, tzinfo=UTC)
+    rows = [_row(tid, last_check=stale_check)]
+    restore_now = datetime(2026, 6, 28, 12, 0, tzinfo=UTC)
+    restored, stale = AgentOrchestrator._partition_respawn_rows(
+        rows, {tid: "in_progress"}, now=restore_now
+    )
+    assert stale == []
+    assert restored[("be-pm", str(tid))]["last_check"] == restore_now
+    assert restored[("be-pm", str(tid))]["last_check"] != stale_check
+
+
 # --------------------------------------------------------------------------- #
 # Startup loader
 # --------------------------------------------------------------------------- #