fix: harden skipped ledger resolution paths

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

tests/adapters/persistence/test_ledger_skip_store.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import threading
 from datetime import UTC, date, datetime
 from uuid import uuid4
 
@@ -87,3 +88,76 @@ def test_ledger_skip_store_filters_and_resolves(pg_clean):
     assert len(resolved) == 1
     assert resolved[0].status == "resolved"
     assert resolved[0].resolution_reason == "manual_ledger_backfill"
+
+
+def test_ledger_skip_store_resolves_null_execution_id_on_backfill(pg_clean):
+    store = PostgreSQLLedgerSkipStore(pg_clean)
+    slot_id = uuid4()
+    record, _ = store.record_skip(
+        instance_key="inst-1",
+        slot_id=slot_id,
+        portfolio_id="PF-1",
+        symbol="005930",
+        order_id="O-3",
+        execution_id=None,
+        side="buy",
+        qty=1.0,
+        price=1010.0,
+        executed_at=datetime(2026, 8, 24, 3, 0, tzinfo=UTC),
+        order_venue="SOR",
+        execution_venue="unknown",
+        skip_reason="missing_execution_id",
+    )
+
+    resolved = store.resolve_for_fill(
+        instance_key="inst-1",
+        slot_id=slot_id,
+        side="buy",
+        order_id="O-3",
+        execution_id="E-3",
+        resolution_reason="manual_ledger_backfill",
+    )
+
+    assert [row.skip_key for row in resolved] == [record.skip_key]
+    assert resolved[0].execution_id == "E-3"
+    assert resolved[0].status == "resolved"
+
+
+def test_ledger_skip_store_retries_unique_violation_during_concurrent_dedupe(pg_clean):
+    slot_id = uuid4()
+    start = threading.Barrier(2)
+    results = []
+
+    def worker():
+        store = PostgreSQLLedgerSkipStore(pg_clean)
+        start.wait()
+        results.append(
+            store.record_skip(
+                instance_key="inst-1",
+                slot_id=slot_id,
+                portfolio_id="PF-1",
+                symbol="005930",
+                order_id="O-4",
+                execution_id=None,
+                side="buy",
+                qty=1.0,
+                price=1111.0,
+                executed_at=datetime(2026, 8, 24, 4, 0, tzinfo=UTC),
+                order_venue="SOR",
+                execution_venue="unknown",
+                skip_reason="missing_execution_id",
+            )
+        )
+
+    t1 = threading.Thread(target=worker)
+    t2 = threading.Thread(target=worker)
+    t1.start()
+    t2.start()
+    t1.join()
+    t2.join()
+
+    assert len(results) == 2
+    assert len({record.skip_key for record, _notify in results}) == 1
+    assert sorted(notify for _record, notify in results) == [False, True]
+    listed = PostgreSQLLedgerSkipStore(pg_clean).list_records(instance_key="inst-1", status="unresolved")
+    assert len(listed) == 1