feat: use broker-authoritative qty in slots RPC holdings

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

trex_core/application/messaging_handlers.py

@@ -9,10 +9,12 @@ from __future__ import annotations
 import logging
 from datetime import date as date_cls
 from datetime import datetime, timezone
-from typing import Optional
+from typing import Optional, Protocol
 from uuid import UUID
 
 from trex_core.application.intents import BuyIntent, IntentService, SellIntent
+from trex_core.application.account_snapshot import AccountSnapshotUnavailable
+from trex_core.application.broker_port import BalanceItem
 from trex_core.application.messaging import RpcRequest, RpcResponse
 from trex_core.application.portfolio import (
     PauseStore,
@@ -185,6 +187,10 @@ _FILTER_STATUS: dict[str, set[str]] = {
 }
 
 
+class SlotsBrokerQuantityReader(Protocol):
+    def holdings_for_slots_rpc(self) -> tuple[list[BalanceItem], datetime]: ...
+
+
 def make_slots_rpc_handler(
     slot_repo: SlotRepository,
     *,
@@ -197,6 +203,7 @@ def make_slots_rpc_handler(
     ledger_outbox=None,
     max_active_slots: Optional[int] = None,
     strategy_state_store=None,
+    broker_quantity_reader: Optional[SlotsBrokerQuantityReader] = None,
 ):
     """Build the RPC handler for `trex.slots.req` (REQ-073/074/116).
 
@@ -252,6 +259,36 @@ def make_slots_rpc_handler(
             for s in slots
         ]
 
+        broker_qty_by_symbol: dict[str, int] = {}
+        broker_qty_available = False
+        broker_qty_captured_at: Optional[datetime] = None
+        if broker_quantity_reader is not None:
+            try:
+                holdings, broker_qty_captured_at = broker_quantity_reader.holdings_for_slots_rpc()
+                broker_qty_by_symbol = {
+                    str(item.symbol): int(item.hldg_qty)
+                    for item in holdings
+                }
+                broker_qty_available = True
+            except AccountSnapshotUnavailable:
+                broker_qty_available = False
+
+        for row, slot in zip(slot_rows, slots):
+            row["slot_quantity"] = row.get("qty")
+            if slot.status.value != "holding":
+                continue
+            row["broker_quantity_available"] = broker_qty_available
+            row["broker_quantity_captured_at"] = (
+                broker_qty_captured_at.isoformat() if broker_qty_captured_at is not None else None
+            )
+            if broker_qty_available:
+                broker_qty = int(broker_qty_by_symbol.get(str(slot.symbol), 0))
+                row["qty"] = float(broker_qty)
+                row["qty_source"] = "broker"
+            else:
+                row["qty"] = None
+                row["qty_source"] = "unavailable"
+
         # dcy-028 / REQ-073/074·079 (C-1): attach opaque strategy_state map per
         # row via one batched store read (read piggyback — no extra round trip).
         # Only entries matching the slot's current occupancy_seq are surfaced.