feat(slots): additive strategy fields + filter (REQ-116, BAT-055)

trex.slots.req wire 계약 additive 확장 — 기존 소비자(orb/tsl) backward compatible.

- PortfolioItem: strategy_name(Optional[str]) + markets(list) 필드 추가
- hub_read.py: get_portfolios()에서 strategy_name/markets 파싱 추가 (safe default)
- slot_to_dict(): strategy_name/strategy_params/markets 3필드 row에 추가 (SnapshotStore→PortfolioItem 경유)
- make_slots_rpc_handler(): strategy 요청 파라미터 → Python 레벨 후처리 필터 (available_slots 계산 이후, REQ-073 AC-6 불변)
- 테스트: AC-1~8 전수 + hub_read 파싱 + 회귀 갱신 (777 passed, 47 skipped)
- docs/interface-contract.md: 요청 파라미터·응답 행 스키마·소스 테이블·REQ-074 AC-5 주석 갱신

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VHtM5Ws1HKCKQ4JGi6GRb5

trex_core/application/portfolio.py

@@ -30,6 +30,9 @@ class PortfolioItem:
 
     Mirrors portfolio-hub's `list_portfolios_v1` PortfolioItem with **no price
     field** — pricing is the strategy module's concern, not core's.
+
+    REQ-116 (BAT-055): strategy_name and markets added additively.
+    strategy_params already existed; now surfaced in slot_to_dict output.
     """
     portfolio_id: str               # == asset_id, dcy-004 OQ-1
     symbol: str
@@ -37,6 +40,9 @@ class PortfolioItem:
     asset_quantity: float           # integer shares semantically; float for tolerance
     active_strategy_id: Optional[str] = None
     strategy_params: dict = field(default_factory=dict)  # opaque, pass-through
+    # REQ-116 additive fields (BAT-055) — safe defaults for legacy hub responses
+    strategy_name: Optional[str] = None        # portfolio-hub strategy_name; None if absent
+    markets: list = field(default_factory=list)  # portfolio-hub markets list; [] if absent
 
 
 class PortfolioHubReadError(Exception):
@@ -461,13 +467,21 @@ def slot_to_dict(
     }
 
     # hub authority: asset_quantity (hub primary) + cash_balance
+    # REQ-116: strategy_name / strategy_params / markets also from PortfolioItem
     asset_qty: Optional[float] = None
     cash_balance: Optional[float] = None
+    strategy_name_val: Optional[str] = None
+    strategy_params_val: dict = {}
+    markets_val: list = []
     if snapshot_store is not None and s.portfolio_id:
         snap = snapshot_store.get(s.portfolio_id)
         if snap is not None:
             asset_qty = float(snap.item.asset_quantity)
             cash_balance = float(snap.item.cash_balance)
+            # REQ-116 (BAT-055): strategy fields from PortfolioItem (hub authority)
+            strategy_name_val = snap.item.strategy_name
+            strategy_params_val = dict(snap.item.strategy_params)
+            markets_val = list(snap.item.markets)
 
     # qty (slot mirror) vs asset_quantity (hub): divergence → warned=True
     slot_qty = float(s.qty) if s.qty is not None else None
@@ -477,6 +491,10 @@ def slot_to_dict(
     d["cash_balance"] = cash_balance
     d["cash_estimated"] = False  # handler overlays ledger_outbox estimate if available
     d["warned"] = warned
+    # REQ-116 (BAT-055): strategy fields — additive, safe default when hub absent
+    d["strategy_name"] = strategy_name_val
+    d["strategy_params"] = strategy_params_val
+    d["markets"] = markets_val
 
     # watchdog nested object (WatchdogStore)
     if watchdog_store is not None: