feat(runtime): dcy-014 trading_date KST 타임존 분리 + 일일 슬롯 preallocation (BAT-018)

데몬이 시스템 UTC 날짜로 슬롯을 1회만 preallocate 해 trading_date 가 KST 캘린더와
어긋나고 재시작 없이는 다음날 슬롯이 안 생기던 문제(issue #14) 정정.

거버넌스: 전부 change-req (신규 REQ 없음, dcy-014 OQ-3; 스케줄러는 REQ-030 패턴 준용).
- REQ-005: trading_date 를 설정 타임존(기본 Asia/Seoul) 기준 계산(timestamp 는 UTC
  유지). DailyPreallocationScheduler 신규 — TZ 일자당 1회 멱등 fire, 재시작 없이
  다음날 슬롯 자동 생성. setup() 배선 + trex-preallocation 스레드
- REQ-048: TOML trading_timezone/daily_preallocation_time 키 + from_config 전파
- REQ-009: runtime-flows/data-model 정합 + instance.example.toml

OQ-1 기본 00:00(TZ 자정, TOML 설정 가능) / OQ-2 매 캘린더일 생성(거래일 캘린더 후속).
멱등 preallocate 로 중복 tick·다중 인스턴스 중복 생성 0.

검증: 단위 302 passed/32 skipped, 인프라 게이트(PG+RabbitMQ) 334 passed, ruff clean.
신규 test_preallocation_scheduler(고정 clock) + test_instance_config 확장.
BAT-018 release-candidate.

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

trex_core/runtime/daemon.py

@@ -10,6 +10,7 @@ Threads (started in `run()`):
   - execution loop         — broker dispatch + poll + slot transitions + event emit
   - ledger writer          — ledger outbox drain (REQ-019)
   - snapshot scheduler      — daily portfolio-hub snapshot refresh (REQ-030)
+  - preallocation scheduler — daily slot preallocation in trading TZ (REQ-005, dcy-014)
   - safety-sell worker      — forced_close / stop-loss·take-profit / market-close (REQ-037/038/039)
 
 Each consumer/publisher uses its OWN RabbitMQTransport instance because
@@ -21,9 +22,8 @@ from __future__ import annotations
 import logging
 import signal
 import threading
-from datetime import datetime, timezone
-
 from datetime import time as time_cls
+from zoneinfo import ZoneInfo
 
 from trex_core.adapters.broker.paper import PaperBroker
 from trex_core.adapters.ledger import InMemoryLedger, PortfolioHubLedger
@@ -62,6 +62,7 @@ from trex_core.application.portfolio import (
     SnapshotStore,
 )
 from trex_core.application.safety_sell import SafetySellService
+from trex_core.application.preallocation_scheduler import DailyPreallocationScheduler
 from trex_core.application.snapshot_scheduler import SnapshotScheduler
 from trex_core.application.watchdog import WatchdogStore
 from trex_core.domain.slot import SlotService
@@ -167,6 +168,15 @@ class Daemon:
             broker=self.broker,
             schedule_kst=_parse_kst_time(config.snapshot_schedule.kst_time),
         )
+        # dcy-014 / REQ-005: daily slot preallocation in the configured
+        # trading timezone (default KST), so trading_date matches the local
+        # calendar and the next day's slots appear without a restart.
+        self.preallocation_scheduler = DailyPreallocationScheduler(
+            slot_service=self.slot_service,
+            total_slots=config.total_slots,
+            tz=ZoneInfo(config.trading_timezone),
+            schedule_time=_parse_kst_time(config.daily_preallocation_time),
+        )
 
         # Event publisher transport — one dedicated instance for the
         # execution-loop thread (pika is not thread-safe).
@@ -287,12 +297,19 @@ class Daemon:
         except Exception:  # noqa: BLE001
             _log.exception("snapshot scheduler loop crashed")
 
+    def _preallocation_loop(self) -> None:
+        try:
+            self.preallocation_scheduler.run_forever(self.stop, tick_sec=60.0)
+        except Exception:  # noqa: BLE001
+            _log.exception("preallocation scheduler loop crashed")
+
     # ------------------------------------------------------------ lifecycle
     def setup(self) -> None:
         apply_migrations(self.config.dsn)
-        self.slot_service.preallocate_daily_slots(
-            datetime.now(tz=timezone.utc).date(), self.config.total_slots
-        )
+        # dcy-014 / REQ-005: preallocate against the configured trading timezone
+        # (default KST), not the system UTC date. Boot-time run_once ensures the
+        # current TZ-day's slots exist immediately (idempotent).
+        self.preallocation_scheduler.run_once()
         self.execution.reconcile()  # REQ-014 restart recovery
         try:
             self.event_publisher.declare_topology(self.config.instance_key)
@@ -307,6 +324,7 @@ class Daemon:
             ("trex-snapshot-rpc", self._snapshot_rpc_loop),
             ("trex-control-rpc", self._control_rpc_loop),
             ("trex-snapshot-scheduler", self._snapshot_scheduler_loop),
+            ("trex-preallocation", self._preallocation_loop),
             ("trex-safety-sell", self._safety_sell_loop),
         ]
         for name, target in workers: