feat(messaging): OPS-005 이벤트 발행 연결 신뢰성 (BAT-047)

발행 전용 연결의 idle heartbeat 사망 후 첫 발행 유실 결함 제거.
- REQ-091 발행 재시도 + 강제 재연결(_force_reconnect, is_open 불신)
- REQ-092 idle keepalive(execution-loop 단일스레드 틱, process_data_events time_limit=0)
- REQ-093 DLQ 가시성 + emit 실패 ERROR 경보(구조화 로그, dcy-029 재사용)
- REQ-094 baseline 문서 정합(runtime-flows/operations/project-structure)

독립 opus QC PASS-WITH-NOTES → 시정 2건(ruff F401, AC-3 프로덕션 경로) 완료.
554 passed/47 skipped/회귀 0/ruff clean. NFR-1 wire 무회귀(interface-contract diff 0).
BAT-047 release-candidate, REQ-091~094 Implemented. dcy-031. M2 트랙B.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VHtM5Ws1HKCKQ4JGi6GRb5

docs/batches/index.md

@@ -54,3 +54,4 @@
 | BAT-044 | standard | released | REQ-083, REQ-070 (CHG-20260616-01) | dcy-030 (issue #28) | [bat-044](./bat-044_20260616_slippage-tick-size-snapping/) |
 | BAT-045 | standard | released | REQ-084, REQ-085, REQ-087 | dcy-029 (issue #29, P0) | [bat-045](./bat-045_20260616_observability-logging-foundation/) |
 | BAT-046 | standard | released | REQ-086, REQ-088, REQ-089, REQ-090 | dcy-029 (issue #29, P1) | [bat-046](./bat-046_20260616_observability-classification-pnl-runbook/) |
+| BAT-047 | standard | release-candidate | REQ-091, REQ-092, REQ-093, REQ-094 | dcy-031 | [bat-047](./bat-047_20260619_event-publisher-connection-reliability/) |