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/adapters/portfolio/hub_read.py

@@ -160,6 +160,9 @@ class PortfolioHubReadAdapter:
             pid = str(raw.get("portfolio_id") or raw.get("asset_id") or "")
             if not pid:
                 continue
+            # REQ-116 (BAT-055): parse strategy_name and markets additively.
+            # Absent keys or wrong types → safe defaults (None / []).
+            raw_markets = raw.get("markets")
             out.append(PortfolioItem(
                 portfolio_id=pid,
                 symbol=str(raw.get("symbol") or ""),
@@ -167,6 +170,8 @@ class PortfolioHubReadAdapter:
                 asset_quantity=float(raw.get("asset_quantity") or 0.0),
                 active_strategy_id=raw.get("active_strategy_id") or None,
                 strategy_params=dict(raw.get("strategy_params") or {}),
+                strategy_name=raw.get("strategy_name") or None,
+                markets=list(raw_markets) if isinstance(raw_markets, list) else [],
             ))
         return out