[CLAUDE] Docs: tai cau truc cleanup — archive raw, compact migration-todos, update CLAUDE+flows

User request: 'review cap nhat va tai cau truc lai MD sao cho phu hop
voi hien tai, cac phan thua va da dieu chinh co the bo ra luon hoac
cap nhat lai'.

Cleanup highlights:
1. Archive 2 file Phase 0 raw dump → docs/_archive/ (forms-spec-raw 657
   line + workflow-raw 62 line). Update link reference 2 file goc.
2. Compact migration-todos.md 386 → 114 line (-71%). Collapse Phase 0-5
   + Tier 3 + Sessions detailed thanh 1 bang summary. Detail xem session
   logs. Phase 6 iter 1+2 + Phase 7 active checklist.
3. Compact STATUS.md In Progress: bo ~17 row ✅ done (giu chỉ 5+ task
   pending: 3 PE feature gap + 4 optional polish + 2 Ops). Recently Done
   table giu day du history.
4. Update flows/README — tat ca 6 flow ✅ Implemented + them PE row
   reference architecture.md §9.
5. Update docs/CLAUDE.md — project layout co PurchaseEvaluations, _archive,
   skills 6 (3 dom + 3 ops). Roadmap them Phase 6 ✅ + Phase 7 WIP. Lien
   he them prod URL solutions.com.vn + SSH config + login admin.
6. Skill ef-core-migration: 13 migration label.

Net delta: -800 line docs (chu yeu archive + collapse migration-todos).

docs/workflow-contract.md

@@ -1,7 +1,7 @@
 # Workflow — Quy trình trình ký Hợp đồng TP/NCC/Tổ đội
 
 > **Nguồn:** `QUY_TRINH/QT TRINH KY HOP DONG TP-NCC.docx`
-> **Raw dump:** [`workflow-raw.md`](workflow-raw.md)
+> **Raw dump:** [`_archive/workflow-raw.md`](_archive/workflow-raw.md) — Phase 0 (archived)
 > **Phase 3 deliverable:** Implement state machine + role guard + SLA timer + notification
 
 ## 1. Phạm vi