feat(safety-sell): dcy-007 core 자율 안전 매도 — BAT-010 기반 + BAT-011 트리거

dcy-007(core 자율 안전 매도) 전체 delivery. BAT-010 기반 인프라가 미커밋
상태였고 BAT-011 트리거 레이어와 공유 파일에서 섞여 있어 한 커밋으로 묶음.

BAT-010 (REQ-034/035/036/041, release-candidate):
- WatchdogStore(application/watchdog.py) + snapshot RPC 워치독 갱신
- Slot stop_loss_price/take_profit_price 필드 + 004_add_price_thresholds.sql
- SlotService.sell() 자율 매도 내부 경로 + idempotency
- SafetySellConfig env 5종 파싱

BAT-011 (REQ-037/038/039/040/042, release-candidate):
- SafetySellService(application/safety_sell.py): forced_close 만기 / stop-loss·
  take-profit KIS polling / 장 마감 강제 청산 + trex-safety-sell 7번째 스레드
- BrokerPort.get_current_price + KIS inquire-price(TTTC8397R/VTTC8397R, stck_prpr)
  + paper stub
- SlotService.update_thresholds() + intent RPC update_thresholds 액션
  (부분 갱신/null 해제, 워치독 last_seen_at 리셋)
- baseline 3문서 정합(interface-contract/runtime-flows/project-structure)

거버넌스: REQ-034~042 Implemented 동기화, BAT-010/011 release-candidate,
dcy-007 discovery 포함.

검증: 신규 38 테스트 green, 단위 236 passed/23 skipped,
인프라 게이트(PG+RabbitMQ) 259 passed(마이그레이션 001~004 round-trip 포함),
ruff clean.

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

trex_core/domain/slot/service.py

@@ -12,6 +12,7 @@ from __future__ import annotations
 
 from dataclasses import replace
 from datetime import date, datetime, timezone
+from decimal import Decimal
 from typing import Any, Optional
 from uuid import UUID
 
@@ -24,6 +25,10 @@ from trex_core.domain.slot.models import Slot, SlotCapacity, SlotTransitionRecor
 from trex_core.domain.slot.repository import SlotRepository
 from trex_core.domain.slot.state import SLOT_ADVISORY_LOCK_ID, SlotState, is_allowed_transition
 
+# Sentinel distinguishing "field omitted (keep current)" from "field set to
+# None (clear threshold)" in update_thresholds (REQ-040 AC-4 vs AC-5).
+_UNSET: Any = object()
+
 
 class SlotService:
     """Slot lifecycle service. Race-free transitions via advisory lock + transaction."""
@@ -69,6 +74,8 @@ class SlotService:
         portfolio_id: Optional[str] = None,
         sell_strategy_id: Optional[str] = None,
         forced_close_at: Optional[datetime] = None,
+        stop_loss_price: Optional[Decimal] = None,
+        take_profit_price: Optional[Decimal] = None,
         extra: Optional[dict[str, Any]] = None,
     ) -> Slot:
         """Transition slot from one state to another atomically.
@@ -115,6 +122,8 @@ class SlotService:
                 portfolio_id=portfolio_id,
                 sell_strategy_id=sell_strategy_id,
                 forced_close_at=forced_close_at,
+                stop_loss_price=stop_loss_price,
+                take_profit_price=take_profit_price,
             )
             self._repo.update_slot(updated)
 
@@ -155,6 +164,8 @@ class SlotService:
         portfolio_id: Optional[str] = None,
         sell_strategy_id: Optional[str] = None,
         forced_close_at: Optional[datetime] = None,
+        stop_loss_price: Optional[Decimal] = None,
+        take_profit_price: Optional[Decimal] = None,
     ) -> Slot:
         """Compute the post-transition Slot row.
 
@@ -181,6 +192,8 @@ class SlotService:
                 portfolio_id=None,
                 sell_strategy_id=None,
                 forced_close_at=None,
+                stop_loss_price=None,
+                take_profit_price=None,
                 updated_at=datetime.now(tz=timezone.utc),
             )
 
@@ -211,9 +224,86 @@ class SlotService:
             forced_close_at=(
                 forced_close_at if forced_close_at is not None else slot.forced_close_at
             ),
+            stop_loss_price=(
+                stop_loss_price if stop_loss_price is not None else slot.stop_loss_price
+            ),
+            take_profit_price=(
+                take_profit_price if take_profit_price is not None else slot.take_profit_price
+            ),
             updated_at=datetime.now(tz=timezone.utc),
         )
 
+    # ------------------------------------------------------------
+    # sell  (REQ-036 / BAT-010)
+    # ------------------------------------------------------------
+    def sell(self, slot_id: UUID, actor: str, reason: str) -> None:
+        """Trigger an autonomous safety-sell for a holding slot (REQ-036).
+
+        Idempotent: silently returns if the slot is already pending_sell.
+        Raises SlotNotFoundError if slot_id is unknown.
+        Raises SlotTransitionError if the slot is neither holding nor pending_sell.
+        """
+        slot = self._repo.fetch_slot(slot_id)
+        if slot is None:
+            raise SlotNotFoundError(f"slot not found: {slot_id}")
+        if slot.status is SlotState.PENDING_SELL:
+            return  # already in progress — idempotent (REQ-036 AC-2)
+        if slot.status is not SlotState.HOLDING:
+            raise SlotTransitionError(
+                f"sell() requires holding state, got: {slot.status.value}"
+            )
+        self.transit_slot(
+            slot_id,
+            SlotState.HOLDING,
+            SlotState.PENDING_SELL,
+            reason=reason,
+            actor=actor,
+        )
+
+    # ------------------------------------------------------------
+    # update_thresholds  (REQ-040 / BAT-011)
+    # ------------------------------------------------------------
+    def update_thresholds(
+        self,
+        slot_id: UUID,
+        *,
+        stop_loss_price: Any = _UNSET,
+        take_profit_price: Any = _UNSET,
+        forced_close_at: Any = _UNSET,
+        actor: str = "strategy",
+    ) -> str:
+        """Partially update a holding slot's safety-sell thresholds (REQ-040).
+
+        Each of the three fields is independent: pass `_UNSET` (the default —
+        i.e. omit the kwarg) to keep the current value, or pass an explicit
+        value (including ``None``) to set/clear it (AC-4 vs AC-5).
+
+        Returns "updated" on success, or "ignored" when the slot is not in
+        the holding state (AC-6). Raises SlotNotFoundError for unknown slots.
+        The caller (RPC handler) resets the watchdog last_seen_at (AC-3).
+        """
+        with self._repo.transactional_advisory_lock(SLOT_ADVISORY_LOCK_ID):
+            slot = self._repo.fetch_slot(slot_id)
+            if slot is None:
+                raise SlotNotFoundError(f"slot not found: {slot_id}")
+            if slot.status is not SlotState.HOLDING:
+                return "ignored"  # not_holding (AC-6)
+            updated = replace(
+                slot,
+                stop_loss_price=(
+                    slot.stop_loss_price if stop_loss_price is _UNSET else stop_loss_price
+                ),
+                take_profit_price=(
+                    slot.take_profit_price if take_profit_price is _UNSET else take_profit_price
+                ),
+                forced_close_at=(
+                    slot.forced_close_at if forced_close_at is _UNSET else forced_close_at
+                ),
+                updated_at=datetime.now(tz=timezone.utc),
+            )
+            self._repo.update_slot(updated)
+            return "updated"
+
     # ------------------------------------------------------------
     # get_today_entry_count
     # ------------------------------------------------------------