PINK DITAv2 L3: fix live LIMIT cancel (kernel order-id propagation + truth-based cancel)

L3 live validation surfaced a live-only defect: a working LIMIT order could not
be cancelled (MARKET never exercised cancel — synchronous fills).

Two coupled fixes:
- Rust FSM (lib.rs): propagate the venue's order id onto the active order for
  ALL order types and event kinds (ACK/partial/full fill) whenever the exchange
  provides one — orders are created at submit with an empty venue_order_id, so a
  later cancel had no real id to reference. Only fills empty ids, never overwrites.
  Requires recompiling libdita_v2_kernel.so.
- Backend (bingx_direct.py): add cancel(order) — a properly-signed DELETE by
  orderId (clientOrderId fallback) with TRUTH-BASED confirmation: BingX can return
  transient errors ("order not exist", dup-within-1s from an internal retry) even
  when the order was removed, so the cancel succeeds iff the order is no longer
  open on the venue. The venue adapter prefers this backend cancel over its raw
  signed_delete fallback (which failed signature with an empty id).

Validated:
- Offline: 63 + new cancel-truth unit tests green (no regression post-recompile).
- Live VST: resting SHORT LIMIT (+5%) rests as ENTRY_WORKING, confirmed as a LIMIT
  open order, cancel -> CANCEL_ACK -> IDLE, exchange flat (test_pink_limit_live.py).
- Live VST MARKET run-through re-validated post-recompile: PASS, exact capital
  reconciliation, two-phase rows visible (ORDER_REQUESTED + ENTRY_FILLED/EXIT).

LIMIT remains execution-infra only; PINK policy stays MARKET. BLUE untouched.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

prod/tests/test_bingx_direct_limit_order.py

@@ -71,3 +71,37 @@ def test_limit_without_valid_price_falls_back_to_market():
     captured: dict = {}
     asyncio.run(_adapter(captured).submit_intent(_intent({"_order_type": "LIMIT", "_limit_price": 0.0})))
     assert captured["order"]["type"] == "MARKET", captured["order"]
+
+
+# --- cancel: truth-based confirmation (trust exchange state over the response) ---
+
+def _cancel_adapter(*, open_after: list):
+    a = BingxDirectExecutionAdapter.__new__(BingxDirectExecutionAdapter)
+    a._config = SimpleNamespace(recv_window_ms=5000)
+    a._instrument_venue_symbol = lambda asset: "TRX-USDT"
+
+    async def _signed_delete(path, params):
+        # Simulate BingX returning a transient error even when the order is removed.
+        return {"status": "REJECTED", "msg": "order not exist"}
+
+    async def _signed_get(path, params):
+        return {"data": {"orders": open_after}}
+
+    a._client = SimpleNamespace(signed_delete=_signed_delete, signed_get=_signed_get)
+    return a
+
+
+def _order(oid="2060963645141028864"):
+    return SimpleNamespace(venue_order_id=oid, venue_client_id="T:i", metadata={"asset": "TRXUSDT"})
+
+
+def test_cancel_succeeds_when_order_gone_despite_error_response():
+    a = _cancel_adapter(open_after=[])  # order no longer open
+    resp = asyncio.run(a.cancel(_order()))
+    assert resp["status"] == "CANCELED", resp
+
+
+def test_cancel_rejected_when_order_still_open():
+    a = _cancel_adapter(open_after=[{"orderId": "2060963645141028864", "status": "PENDING"}])
+    resp = asyncio.run(a.cancel(_order()))
+    assert resp["status"] != "CANCELED", resp