docs(dcy-010): draft-req + confirm-req — REQ-046~051 Approved (daemon-scoped broker credential provisioning)

Adds SRS specification documents for daemon-scoped broker credential management:
- REQ-046: Broker credential daemon_id field
- REQ-047: Migration PKv1→PKv2 with daemon_id
- REQ-048: Backfill existing broker credentials with daemon_id
- REQ-049: User info endpoint including daemon-scoped credentials
- REQ-050: Credential CLI --daemon-id option
- REQ-051: Security isolation per daemon boundary

Updates dcy-010 discovery document with generated REQ references and register.

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

docs/discovery/dcy-010_20260627_daemon-scoped-broker-credential-provisioning.md

@@ -8,7 +8,7 @@
 - 마지막 갱신 시각(KST): 2026-06-28
 - 대체됨: 없음
 - 후속 Discovery 참조: trex-core 소비자측 day-start fetch + fail-safe 로드 = 별도 trex-core Discovery로 분리 **확정**(2026-06-28). trex-core repo에 신규 Discovery 생성 예정(미생성).
-- 생성된 REQ 참조: 없음
+- 생성된 REQ 참조: REQ-046, REQ-047, REQ-048, REQ-049, REQ-050, REQ-051
 
 # 1. 계획 상태 요약
 현재 Discovery가 어떤 배경에서 작성되고 있는지, 연계 문서가 있는지, 지금 시점의 해석이 무엇인지 짧게 요약한다.