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/adapters/persistence/postgresql.py

@@ -131,6 +131,74 @@ class PostgreSQLSlotRepository:
                 row = cur.fetchone()
                 return self._row_to_slot(row) if row else None
 
+    # --- asset-centric (dcy-020 / BAT-028) ---
+    def find_slot_by_portfolio(self, instance_key: str, portfolio_id: str) -> Optional[Slot]:
+        with self._psycopg.connect(self._dsn) as conn:
+            with conn.cursor() as cur:
+                cur.execute(
+                    f"SELECT {_SLOT_COLUMNS} FROM daily_slot "
+                    "WHERE instance_key = %s AND portfolio_id = %s LIMIT 1",
+                    (instance_key, portfolio_id),
+                )
+                row = cur.fetchone()
+                return self._row_to_slot(row) if row else None
+
+    def count_active(self, instance_key: str) -> int:
+        with self._psycopg.connect(self._dsn) as conn:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT count(*) FROM daily_slot WHERE instance_key = %s "
+                    "AND status IN ('holding','pending_buy','pending_sell')",
+                    (instance_key,),
+                )
+                row = cur.fetchone()
+                return int(row[0]) if row else 0
+
+    def reconcile_universe(
+        self, instance_key: str, trading_date: date, universe_portfolio_ids: set[str],
+        *, allow_retire: bool = True,
+    ) -> dict[str, int]:
+        now = datetime.now(tz=timezone.utc)
+        created = retired = tombstoned = 0
+        with self._psycopg.connect(self._dsn, autocommit=False) as conn:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT portfolio_id, status, retired_at FROM daily_slot "
+                    "WHERE instance_key = %s AND portfolio_id IS NOT NULL",
+                    (instance_key,),
+                )
+                existing = {r[0]: (r[1], r[2]) for r in cur.fetchall()}
+                # create new asset slots (idempotent via partial unique)
+                for pid in universe_portfolio_ids:
+                    if pid in existing:
+                        continue
+                    cur.execute(
+                        "INSERT INTO daily_slot "
+                        "(slot_id, trading_date, status, instance_key, portfolio_id, "
+                        "created_at, updated_at) VALUES (%s, %s, 'idle', %s, %s, %s, %s) "
+                        "ON CONFLICT (instance_key, portfolio_id) "
+                        "WHERE portfolio_id IS NOT NULL DO NOTHING",
+                        (uuid4(), trading_date, instance_key, pid, now, now),
+                    )
+                    created += cur.rowcount
+                # retire / tombstone assets that left the universe (skipped under
+                # the mass-disappearance guard, dcy-020/OQ-2 D3)
+                if allow_retire:
+                    for pid, (status, retired_at) in existing.items():
+                        if pid in universe_portfolio_ids:
+                            continue
+                        if status in ("holding", "pending_buy", "pending_sell"):
+                            tombstoned += 1
+                        elif retired_at is None:
+                            cur.execute(
+                                "UPDATE daily_slot SET retired_at = %s, updated_at = %s "
+                                "WHERE instance_key = %s AND portfolio_id = %s",
+                                (now, now, instance_key, pid),
+                            )
+                            retired += 1
+                conn.commit()
+        return {"created": created, "retired": retired, "tombstoned": tombstoned}
+
     def update_slot(self, slot: Slot) -> None:
         with self._psycopg.connect(self._dsn, autocommit=False) as conn:
             with conn.cursor() as cur: