feat(config): expose paper broker tuning via env (REQ-010 AC-5, BAT-009)

Wire the existing PaperBroker scenario knobs (fill_after_polls /
qty_per_poll / reject_symbols) to daemon env so REQ-011 AC-2 e2e
scenarios (delayed / partial / reject) can be reproduced by a daemon
restart. Unset == prior PaperBroker() behaviour, byte-for-byte (no
regression).

- config.py: PaperBrokerConfig + from_env parsing (TREX_PAPER_*)
- daemon.py: _build_broker injects config.paper into PaperBroker
- .env.example: document the 3 paper tuning keys (paper-only, e2e)
- tests: paper broker defaults + env tuning parsing

SDLC: REQ-010 CHG-20260606-01 (AC-5 added) / -02 (Implemented);
BAT-009 batch-lite release-candidate; REL-001 feedback handoff records
pre-deployment e2e observations incl. event-publisher idle-drop and
paper correlation_id collision (GitHub #4, #5).

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

docs/releases/index.md

@@ -8,4 +8,4 @@
 
 | REL ID | Profile | Status | Included Batch | Discovery/REQ Input | Link |
 | --- | --- | --- | --- | --- | --- |
-| REL-001 | app-service | confirmed | BAT-001~008 | Discovery: orb-v1 전략 모듈 / Change-req: REQ-030 옵션 D, 전략 필드 실데이터 | [rel-001](rel-001_20260606_trex-core-slot-core-baseline.md) |
+| REL-001 | app-service | confirmed | BAT-001~008 | Discovery: orb-v1 전략 모듈, 부분 매도(#5) / Change-req: REQ-030 옵션 D, 전략 필드 실데이터, 이벤트 publisher idle 견고성, paper execution_id Redis(#4) | [rel-001](rel-001_20260606_trex-core-slot-core-baseline.md) |