refactor: 缠论引擎包化与 Web 分层（ECR-001）

将根目录引擎迁入 chanlun/ 并保留兼容 shim；拆分 TF_DF 与 web 服务；
前端模块化；strategies 改用 chanlun 导入；补充 ESS 文档与 golden 回归。

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/HANDOFF/ECR-001-architect-to-engineer.md

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+# Handoff
+
+**From:** ARCHITECT  
+**To:** ENGINEER  
+**ECR:** ECR-001  
+**State:** design → coding  
+**Date:** 2026-08-05  
+
+## Artifacts
+
+- [x] ECR (Approved)
+- [x] PRODUCT_SPEC
+- [x] ENGINEERING_SPEC
+- [x] RISK_REVIEW (N/A)
+- [x] ADR-001
+- [x] TRACEABILITY
+- [ ] TEST_REPORT / CODE_REVIEW / EXP (engineer / reviewer)
+
+## Restrictions — Do not modify
+
+- `config/`、`strategies/` 内容
+- 缠论算法语义、`/api/analyze` 破坏性变更
+- 计划文件本身
+
+## Goal for receiver
+
+按 ENGINEERING_SPEC 完成包化、TF_DF 拆分、Web 分层、前端模块化、golden 测试与文档收尾。
+
+## Done for this hop
+
+- [x] ESS docs 落盘
+- [x] ECR Approved（计划实施授权）
+
+## References
+
+- `docs/ECR/ECR-001-chan-web-restructure.md`
+- `docs/ENGINEERING_SPEC/ECR-001-restructure.md`
+- Plan: ESS Chan Refactor（1B+2B）

docs/HANDOFF/ECR-001-engineer-to-reviewer.md

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+# Handoff
+
+**From:** ENGINEER  
+**To:** REVIEWER  
+**ECR:** ECR-001  
+**State:** coding → review  
+**Date:** 2026-08-05  
+
+## Artifacts
+
+- [x] ECR (Approved / Done pending review)
+- [x] PRODUCT_SPEC / ENGINEERING_SPEC / ADR / RISK N/A
+- [x] IMPLEMENTATION_REPORT
+- [x] TEST_REPORT
+- [ ] CODE_REVIEW
+
+## Goal for receiver
+
+对照 ECR-001 Acceptance 做代码审阅；确认 strategies/config 无 diff；golden 与路由契约通过。
+
+## References
+
+- `docs/IMPLEMENTATION_REPORT/ECR-001.md`
+- `docs/TEST_REPORT/ECR-001.md`
+- `docs/CHANGELOG/CHANGELOG.md`