sched: typed history recorder with exactly-once terminal reconcile (F4)

src/wf_scheduling/store.py

@@ -168,6 +168,29 @@ class FileScheduleStore:
             entries.append(record.model_dump(mode="json"))
             self._write_json(path, entries)
 
+    def has_history_entry(
+        self,
+        schedule_id: str,
+        *,
+        run_id: str,
+        kind: str,
+        checkpoint_id: str | None = None,
+    ) -> bool:
+        """Whether this exact stopped result already has a history entry.
+
+        Idempotency identity is ``(run_id, kind, checkpoint_id)``: repeats
+        of one recovery pass dedup, while a resumed run that stops again
+        (new checkpoint id) records a new entry.
+        """
+        for item in self._read_history_locked(schedule_id):
+            if (
+                item.get("run_id") == run_id
+                and item.get("kind") == kind
+                and item.get("checkpoint_id") == checkpoint_id
+            ):
+                return True
+        return False
+
     @staticmethod
     def _sort_key(
         item: OccurrenceRecord,