feat(intents): dcy-011 buy intent portfolio_id 필수 계약 + ledger skip 가시화 (BAT-015)

dcy-011 전 주기 delivery. issue #6(buy 식별자 정정) + issue #11(ledger silent skip) 흡수.
거버넌스: 기존 Implemented REQ는 change-req, 신규 기능만 신규 REQ(OQ-3).

- REQ-007 (change-req): buy admission portfolio_id 필수화 + SnapshotStore symbol
  resolve + unknown_portfolio 거부 (hard cutover, OQ-1/OQ-2)
- REQ-021 (change-req): buy 메시지 payload symbol 제거
- REQ-018 (change-req): _record_ledger skip 가시화 (WARN + ledger_skipped 카운터)
- REQ-055 (신규): closed↔ledger_outbox anti-join 운영 점검 find_ledger_gap_slots

코드: intents.py(BuyIntent portfolio_id 필수 + resolve_symbol 주입 + _admit_buy
reject 분기), messaging_handlers.py, runtime/daemon.py(_resolve_symbol 배선),
execution.py(skip WARN 로그), adapters/persistence/ops_checks.py(신규 anti-join).

검증: 단위 282 passed/32 skipped, 인프라 게이트(PG+RabbitMQ) 314 passed, ruff clean.
BAT-015(standard) release-candidate. srs/index Next ID → REQ-056.

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

trex_core/application/messaging_handlers.py

@@ -71,16 +71,18 @@ def make_intent_rpc_handler(
         intent_type = str(body.get("intent_type") or "").lower()
         try:
             if intent_type == "buy":
+                # dcy-011 / REQ-021: buy payload carries portfolio_id (required);
+                # symbol is NOT a client field — admission resolves it from the
+                # universe. portfolio_id absence is rejected at admission (FR-1).
                 buy = BuyIntent(
                     intent_id=intent_id,
                     trading_date=_parse_date(body.get("trading_date")),
-                    symbol=str(body.get("symbol") or ""),
+                    portfolio_id=_opt_str(body.get("portfolio_id")) or "",
                     qty=_opt_float(body.get("qty")),
                     allocated_capital=_opt_float(body.get("allocated_capital")),
                     entry_price=_opt_float(body.get("entry_price")),
                     strategy_id=_opt_str(body.get("strategy_id")),
                     sell_strategy_id=_opt_str(body.get("sell_strategy_id")),
-                    portfolio_id=_opt_str(body.get("portfolio_id")),
                     forced_close_at=_opt_dt(body.get("forced_close_at")),
                     stop_loss_price=_opt_decimal(body.get("stop_loss_price")),
                     take_profit_price=_opt_decimal(body.get("take_profit_price")),