fix(execution): cancel SQL nullable type error, KIS child cancel detection, worker exception logging

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

tests/application/test_execution_cancel.py

@@ -179,3 +179,49 @@ def test_operator_cancel_is_sent_once_across_repeat_and_restart():
     assert restarted.cancel_pending_slot(sid) == "cancel_already_recorded"
     assert broker.cancel_calls == 1
     assert repo.fetch_slot(sid).cancel_state == CancelState.REQUESTED.value
+
+
+# ── Regression: first-cancel reservation (retry_before=None) ─────────────────
+
+def test_first_cancel_reservation_with_no_retry_before_succeeds():
+    """First cancel reservation with retry_before=None must reserve exactly once (fix for
+    PostgreSQL IndeterminateDatatype; the in-memory repo mirrors the corrected SQL path)."""
+    broker = ProgrammableBroker()
+    repo, svc, intents, execution, _, _ = _wire(broker)
+    sid = _buy_to_holding(intents, execution)
+    intents.submit_sell(SellIntent(intent_id="s1", slot_id=sid))
+    broker.responder = lambda side: FillStatus(state="accepted")
+    execution.run_once()  # dispatch
+
+    # First operator cancel — retry_before=None path
+    result = execution.cancel_pending_slot(sid)
+    assert result == "ok", f"expected ok, got {result}"
+    assert broker.cancel_calls == 1
+    # Second call must be idempotent (cancel_state already set)
+    result2 = execution.cancel_pending_slot(sid)
+    assert result2 == "cancel_already_recorded"
+    assert broker.cancel_calls == 1  # no second broker call
+
+
+def test_timeout_cancel_first_attempt_with_retry_before_none():
+    """Timeout cancel's first attempt passes retry_before=None; must call broker once."""
+    broker = ProgrammableBroker()
+    repo, svc, intents, execution, _, _ = _wire(broker)
+    sid = _buy_to_holding(intents, execution)
+    intents.submit_sell(SellIntent(intent_id="s1", slot_id=sid))
+    broker.responder = lambda side: FillStatus(
+        state="accepted",
+        raw={"order_open_confirmed": True},
+    )
+    execution.run_once()  # dispatch
+
+    # Simulate timeout: set order_submitted_at well in the past
+    s = repo.fetch_slot(sid)
+    repo._slots[sid] = replace(
+        s,
+        order_submitted_at=datetime.now(tz=timezone.utc) - timedelta(seconds=120),
+        order_date="20260901",
+        timeout_sec=30,
+    )
+    execution.run_once()  # should trigger timeout cancel
+    assert broker.cancel_calls == 1