feat(slot): BAT-028 M2/M3 — universe reconcile + 자산 중심 admission (dcy-020/REQ-058·059)

config 게이트 이중 경로(max_active_slots 설정 시 자산 중심, 미설정 시 legacy pool).
운영 데몬은 cutover(BAT-δ) 전까지 pool 무중단.

- repository: find_slot_by_portfolio·count_active(holding+pending_buy+pending_sell)·
  reconcile_universe(생성 멱등/soft-retire/tombstone, allow_retire 가드) — protocol+in_memory+PG
  (PG: ON CONFLICT (instance_key, portfolio_id) WHERE portfolio_id IS NOT NULL)
- snapshot_scheduler: run_once swap 직후 _reconcile_slots(빈 universe skip, ≥50%↓ retire 보류)
- intents: _admit_buy 모드 분기 + _admit_buy_asset_centric(활성화/already_active/
  capacity_full/unknown_portfolio/over-cap, 인스턴스 lock)
- daemon: instance_key·max_active_slots·reconcile_enabled·trading_date_fn 배선
- 신규 테스트: test_universe_reconcile(6), test_asset_centric_admission(6), PG reconcile(1)

검증: 단위 387 passed / 35 skipped, PG-gated 17 passed, ruff clean. legacy 무파손.
REQ-058/059/060 은 Approved 유지(자산 중심 경로 도입 검증; default 전환·cutover 는 BAT-δ).

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

trex_core/domain/slot/in_memory_repository.py

@@ -100,6 +100,54 @@ class InMemorySlotRepository:
             raise SlotNotFoundError(f"slot not found: {slot.slot_id}")
         self._slots[slot.slot_id] = slot
 
+    # --- asset-centric (dcy-020 / BAT-028) ---
+    _ACTIVE = (SlotState.HOLDING, SlotState.PENDING_BUY, SlotState.PENDING_SELL)
+
+    def find_slot_by_portfolio(self, instance_key: str, portfolio_id: str) -> Optional[Slot]:
+        for s in self._slots.values():
+            if s.instance_key == instance_key and s.portfolio_id == portfolio_id:
+                return s
+        return None
+
+    def count_active(self, instance_key: str) -> int:
+        return sum(
+            1 for s in self._slots.values()
+            if s.instance_key == instance_key and s.status in self._ACTIVE
+        )
+
+    def reconcile_universe(
+        self, instance_key: str, trading_date: date, universe_portfolio_ids: set[str],
+        *, allow_retire: bool = True,
+    ) -> dict[str, int]:
+        existing = {
+            s.portfolio_id: s for s in self._slots.values()
+            if s.instance_key == instance_key and s.portfolio_id is not None
+        }
+        now = datetime.now(tz=timezone.utc)
+        created = retired = tombstoned = 0
+        # create asset slots for newly-appeared universe assets (idempotent)
+        for pid in universe_portfolio_ids:
+            if pid not in existing:
+                sid = uuid4()
+                self._slots[sid] = Slot(
+                    slot_id=sid, trading_date=trading_date, status=SlotState.IDLE,
+                    instance_key=instance_key, portfolio_id=pid,
+                    created_at=now, updated_at=now,
+                )
+                created += 1
+        # retire / tombstone assets that left the universe (skipped under the
+        # mass-disappearance guard, dcy-020/OQ-2 D3 — caller passes allow_retire=False)
+        if allow_retire:
+            for pid, s in existing.items():
+                if pid in universe_portfolio_ids:
+                    continue
+                if s.status in self._ACTIVE:
+                    tombstoned += 1  # holding/pending — keep (safety-sell), no retire
+                elif s.retired_at is None:
+                    self._slots[s.slot_id] = replace(s, retired_at=now, updated_at=now)
+                    retired += 1
+        return {"created": created, "retired": retired, "tombstoned": tombstoned}
+
     # --- slot_transition_log (append-only) ---
     def append_transition_log(self, record: SlotTransitionRecord) -> None:
         # Defensive copy; reject any external mutation attempt on the list.

trex_core/domain/slot/repository.py

@@ -63,6 +63,34 @@ class SlotRepository(Protocol):
         """Persist slot row (UPDATE by slot_id)."""
         ...
 
+    # --- asset-centric (dcy-020 / BAT-028) ---
+    def find_slot_by_portfolio(self, instance_key: str, portfolio_id: str) -> Optional[Slot]:
+        """Return the (single, permanent) slot bound to `portfolio_id` for this
+        instance (dcy-020/REQ-059), or None. Keyed by (instance_key, portfolio_id)
+        — independent of trading_date."""
+        ...
+
+    def count_active(self, instance_key: str) -> int:
+        """Count position-occupying slots for this instance — status in
+        {holding, pending_buy, pending_sell} (dcy-020/REQ-059 M cap, D2)."""
+        ...
+
+    def reconcile_universe(
+        self, instance_key: str, trading_date: date, universe_portfolio_ids: set[str],
+        *, allow_retire: bool = True,
+    ) -> dict[str, int]:
+        """Reconcile the slot set to the portfolio-hub universe (dcy-020/REQ-058).
+
+        - new portfolio_id (no slot for instance) -> create an inactive asset slot
+          (idempotent; keyed by (instance_key, portfolio_id), permanent).
+        - slot whose portfolio_id left the universe AND is inactive AND not yet
+          retired -> soft-retire (set retired_at).
+        - slot that left the universe but is holding/pending -> tombstone (left
+          as-is; not retired).
+        Returns counts {created, retired, tombstoned}. Degrade / mass-disappearance
+        guards are the caller's responsibility (scheduler)."""
+        ...
+
     # --- slot_transition_log (append-only) ---
     def append_transition_log(self, record: SlotTransitionRecord) -> None:
         """Append one row to slot_transition_log (no UPDATE/DELETE allowed)."""