feat: add HK safe-haven symbols + lot-size rounding helper

- Add _HK_SAFE_HAVEN_SYMBOLS (02800 TraHK, 82800 RMB counter)
- _symbol_role() now recognizes HK safe-haven symbols
- Add _floor_lot_quantity() for HK board lot rounding

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

Author: Pigbibi

application/execution_service.py

@@ -574,6 +574,12 @@ def _floor_whole_share_quantity(quantity):
     return normalize_order_quantity(floor_to_quantity_step(quantity, 1.0))
 
 
+def _floor_lot_quantity(quantity, *, lot_size: int = 100):
+    """Floor to the nearest board lot for HK stocks."""
+    step = float(max(1, int(lot_size)))
+    return normalize_order_quantity(floor_to_quantity_step(float(quantity), step))
+
+
 def _normalize_trade_quantity(quantity):
     raw_quantity = max(0.0, float(quantity or 0.0))
     if raw_quantity <= 0.0:

decision_mapper.py

@@ -17,8 +17,10 @@
 from strategy_registry import LONGBRIDGE_PLATFORM, resolve_strategy_definition
 
 _SAFE_HAVEN_SYMBOLS = frozenset({"BOXX", "BIL"})
+_HK_SAFE_HAVEN_SYMBOLS = frozenset({"02800", "82800"})  # TraHK (HKD + RMB counters)
 _INCOME_SYMBOLS = frozenset({"QQQI", "SPYI"})
 _DEFAULT_MIN_TRADE_FLOOR = 100.0
+_DEFAULT_HK_LOT_SIZE = 100  # most HK stocks trade in lots of 100 shares
 _DEFAULT_REBALANCE_THRESHOLD_RATIO = 0.01
 _SNAPSHOT_DIAGNOSTIC_FIELDS = (
     "snapshot_manifest_price_as_of",
@@ -190,7 +192,7 @@ def _cash_by_currency_from_snapshot(snapshot: Any | None) -> dict[str, float]:
 
 def _symbol_role(symbol: str) -> str | None:
     normalized = str(symbol or "").strip().upper()
-    if normalized in _SAFE_HAVEN_SYMBOLS:
+    if normalized in _SAFE_HAVEN_SYMBOLS or normalized in _HK_SAFE_HAVEN_SYMBOLS:
         return "safe_haven"
     if normalized in _INCOME_SYMBOLS:
         return "income"