diff --git a/.claude/agents/README.md b/.claude/agents/README.md
index 97c88e0..52c03cc 100644
--- a/.claude/agents/README.md
+++ b/.claude/agents/README.md
@@ -33,6 +33,21 @@
 
 ---
 
+## 🚨 RULE BẮT BUỘC (S22 chốt cuối — directive Thứ 9)
+
+**Em main BẮT BUỘC phân việc cho sub-agent đúng vai trò khi ACCEPT criteria match.**
+
+Retrospective S22 lesson: Em main solo 6/10 task lẽ ra delegate được (Plan D + Plan C task 1-4 + S22+2 + S22+3 + Plan F pre-flight). KHÔNG fail nhưng vi phạm directive. Token cost overhead + lose multi-agent ROI.
+
+**Workflow forward S23+:**
+- Trước mọi task, classify qua decision tree dưới đây
+- Nếu task qualify Implementer Case 1/2/3/5 → **BẮT BUỘC spawn**, KHÔNG em main solo
+- Nếu task có pre-flight read-only → **BẮT BUỘC spawn Investigator** trước
+- Nếu task có deploy claim → **BẮT BUỘC spawn CICD Monitor** sau push
+- Nếu task có heavy diff / security-sensitive → **BẮT BUỘC spawn Reviewer** pre-commit
+
+Em main solo chỉ khi: schema/UX/architecture decision + cross-stack tight coupling + bug fix reasoning chain.
+
 ## 🔄 Invocation decision tree (em main apply)
 
 Task input → classify task type:
diff --git a/docs/HANDOFF.md b/docs/HANDOFF.md
index c0fdde6..468b50e 100644
--- a/docs/HANDOFF.md
+++ b/docs/HANDOFF.md
@@ -1,6 +1,7 @@
 # HANDOFF — Brief 5 phút cho session tiếp theo
 
-**Last updated:** 2026-05-13 2200 (Session 22 CHỐT — **bro confirm sub-agent solution OK**. 11 commits pushed remote `3d725c4..b04a11a`. CICD Monitor Run #188 PASS verified. State final: **30 mig · 104 test · 47 gotcha (+1 #47) · 19 memory · 6 skills · 4 sub-agents · 33 active users prod**. KHÔNG còn pending push. Plan G S21-S22 evidence: Trial Week 1 → Week 2 sub-agent ROI confirmed. Bro test UAT 4 flag pattern + view file PDF + Section Điều chỉnh ngân sách.)
+**Last updated:** 2026-05-13 2300 (Session 22 CHỐT cuối cùng — **bro chốt directive Thứ 9 BẮT BUỘC delegate sub-agent**. 14 commits pushed remote `3d725c4..2b9788d` + (this final). CICD Monitor Run #193 PASS verified all live endpoints + Mig 30 prod + bundle hash rotated. State final: **30 mig · 104 test · 47 gotcha (#47 revised informational) · 19 memory · 6 skills · 4 sub-agents · 33 active users prod**. Retrospective S22: em main solo 6/10 task lẽ ra delegate được — vi phạm directive Thứ 9. **Forward S23+ rule:** BẮT BUỘC spawn sub-agent khi ACCEPT criteria match (Implementer Case 1/2/3/5, Investigator pre-flight, Reviewer pre-commit, CICD Monitor post-deploy). Em main solo CHỈ khi schema/UX/architecture decision + cross-stack tight coupling + bug fix reasoning chain.)
+**S22 chốt v1:** 2026-05-13 2200 (Session 22 CHỐT — **bro confirm sub-agent solution OK**. 11 commits pushed remote `3d725c4..b04a11a`. CICD Monitor Run #188 PASS verified. State final: **30 mig · 104 test · 47 gotcha (+1 #47) · 19 memory · 6 skills · 4 sub-agents · 33 active users prod**. KHÔNG còn pending push. Plan G S21-S22 evidence: Trial Week 1 → Week 2 sub-agent ROI confirmed. Bro test UAT 4 flag pattern + view file PDF + Section Điều chỉnh ngân sách.)
 **S22 prev:** 2026-05-13 1800 (Session 22 — Plan C + D + E done, Plan F ABORTED pre-flight fail. 5 commits local `60efeed..HEAD` chưa push. Plan D F2 toggle UI (BE+FE Admin). Plan C task 4 + 1-3 — 19 unit test mới (+5 reg #44 + 7 ReturnMode + 7 Guard). Plan E strict V2 scope List + Detail (remove UAT loose `|| ApprovalWorkflowId != null`). Plan F ABORTED — pre-flight prod sqlcmd reveal Contract entity HOÀN TOÀN V1 chưa wire V2 + 4 PE V1-only + 23 PE V1+V2 mix. Defer F sau Plan B Contract V2 wire. State: **29 mig · 103 test (+19) · 46 gotcha · 19 memory · 6 skills · 4 sub-agents (em main solo S22)**. 5 commits pending push `3d725c4..HEAD`.)
 **S21 CHỐT CUỐI:** 2026-05-13 1530 (Session 21 CHỐT CUỐI — 5 turn cumulative `3a34831..c0af9e0` 12 commits pushed remote, CICD Monitor verify 2/2 run PASS. Gotcha #46 mới (Gitea API path/cache stale). 2 memory user-level mới: `feedback_ef_migration_backfill_reorder` + `feedback_per_nv_permission_scope`. 3 agent Inv/Imp/Rev cập nhật MEMORY ghi recent activity S21 t3-t5 em main solo. State final: **29 mig · 84 test · 46 gotcha · 19 memory · 6 skills · 4 sub-agents (3 seeds + 1 cicd 2-run)**. KHÔNG còn pending push. Plan G Trial Week 1 evidence: CICD spawn 2/2 PASS (green), cost ~110-120K under 150K budget, CI time 3-3.5min stable. Pending Plan C test-after bundle defer sau UAT 2-3 lần ổn.)
 **S21 turn 5:** 2026-05-13 1400 (Session 21 turn 5 — **🎯 Refactor Allow* sang PER-NV (Mig 29). 4 chunk per-commit `0366946` (A BE+Mig 29) → `63234b2` (B FE Admin Designer per-Level 5 checkbox) → `5ccb2a7` (C FE eOffice mirror 2 app rename) → this Chunk D Docs. **F1+F3** 5 flag MOVED xuống `ApprovalWorkflowLevels` (per slot Approver). **F2** MOVED xuống `Users` (per-Drafter). Mig 29 4-stage: ADD 5 Levels + 1 Users + BACKFILL bulk SQL preserve admin config S21 t4 + DROP 6 workflow column. Service refactor đọc `currentLevel.Allow*` + `drafterUser.AllowDrafterSkipToFinal`. DTO `AwLevelDto +5`, `PeDetailBundle.workflowOptions → currentLevelOptions + drafterAllowSkipToFinal`. FE Admin Designer 5 checkbox per Level slot inline (drop section workflow-level). 84 test PASS. CHƯA push remote — chờ bro confirm.**)
@@ -9,6 +10,25 @@
 **S21 turn 2:** 2026-05-12 1800 (Session 21 turn 2 — **🎯 RAG Hybrid setup planning + Cách A validation deep dive. 2 commit (`1f8e9af` plan save 1223 LOC + this chốt). KHÔNG implement, plan only — defer chờ bro confirm 5 dự án future. Decision chốt: Cách A defensive (giữ blanket 120K em main + RAG retrieve) over Cách B aggressive (cắt 60-70% blanket). Industry-validated cross 4 Anthropic blog + 5 community tools (Cursor/Continue/Cline/Aider). Stack: Voyage-3-large + Qdrant + FastMCP + Streamlit dashboard. Multi-agent cost reality: 4 agents → ~520K cumulative blanket → heavy session ~560K (Cách A) vs ~700K (lazy). 3-layer pattern Phase 1-3 rollout (embeddings + BM25 + reranking, ~70% → ~92% recall). Stats: +1 memory entry (`feedback_rag_hybrid_pattern`) +1 plan file (`rag-setup-plan.md` 1500 LOC). Sub-agents vẫn 4 seeds-only, em main solo session.**)
 **S21 turn 1:** 2026-05-12 0030 (Session 21 turn 1 — **🎯 Add con thứ 4 cicd-monitor (Path A — post-deploy verifier). 1 commit `f1c61c9` pushed `36e21c8..f1c61c9 main -> main`. CI skipped per path filter (3 file `.md`). Cost reality update: ~750K spawn (3 → 4 agents) · ~1.35M heavy / ~700K optimized. Stats: 4 sub-agents seeds-only · 16 memory · 27 mig · 59 tables · ~142 endpoints · 81 test · 44 gotcha · 6 skills unchanged. KHÔNG flush 3 agent MEMORY.md (chưa spawn work — em main solo). Trial Week 1 kick-off S21 turn 2+ Plan B Contract V2 wire mirror PE pattern.**)
 
+## 🎯 Plan B Contract V2 wire — sub-agent role pre-allocated (S23+ kick off priority)
+
+Per directive Thứ 9 BẮT BUỘC delegate. Workflow forward:
+
+| Chunk | Owner | Justification |
+|---|---|---|
+| **Pre-flight audit Contract entity V1 state** | 🟦 **Investigator** | Read-only scan `Contract.cs` + `ContractDeptApproval.cs` + sqlcmd 7 V1 contract — Case "audit > 5 files" |
+| **Chunk A Mig 31 schema** (Contract +ApprovalWorkflowId +CurrentApprovalLevelOrder) | 🟨 **Implementer Case 2** | Cookie-cutter mirror PE Mig 23 pattern proven 1× S17. Spec deterministic |
+| **Chunk B Service ApproveV2Async branch** | 👤 **Chủ trì Solo** | Cross-stack reasoning chain — Service branch theo pin field + state machine integration |
+| **Chunk C Mig 32 ContractLevelOpinions + Service UPSERT hook** | 🟨 **Implementer Case 2** | Mirror PE Mig 26 + service hook pattern (`feedback_service_hook_vs_endpoint`) |
+| **Chunk D FE ContractCreatePage Workspace Select V2** | 🟨 **Implementer Case 2** | Mirror PeCreate Workspace pattern × 2 app (rule §3.9) |
+| **Chunk E FE ContractDetailContent Section 5 V2** | 🟨 **Implementer Case 2** | Mirror PE Section 5 LevelOpinionsSectionV2 × 2 app |
+| **Pre-commit each chunk review** | 🟥 **Reviewer** | Heavy diff + cross-stack — Smart Friend guard active |
+| **Post-deploy verify Run** | 🟩 **CICD Monitor** | Bundle hash + Mig 31+32 prod + smoke endpoint mới |
+
+Estimated: 5-6 chunk, ~700+ LOC. Em main lead Chunk B (cross-stack reasoning) + coordinate. 4 chunk delegate Implementer (Case 2 cookie-cutter mirror).
+
+---
+
 ## 🎯 Session 21 chốt cuối — 5 turn timeline (2026-05-12 → 2026-05-13)
 
 | Turn | Date/Time | Topic | Commits | CICD verify |