[CLAUDE] Scaffold: khoi tao SOLUTION_ERP Phase 0

- .NET 10 Clean Architecture: Domain/Application/Infrastructure/Api (4 project)
- 2 React + Vite + TS app: fe-admin (:8082), fe-user (:8080) voi proxy /api
- Node engines >=20, .nvmrc = 20 cho CI (bai hoc NamGroup)
- SQL Server 2022 qua docker-compose (dev)
- Parse 8 FORM -> docs/forms-spec.md (catalog + ma HD format RG-001)
- Parse QUY_TRINH -> docs/workflow-contract.md (9 phase state machine + role matrix)
- docs: CLAUDE.md, STATUS.md, PROJECT-MAP.md, migration-todos.md (roadmap 5 phase)
- .claude/skills: 3 placeholder (contract-workflow, form-engine, permission-matrix)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/skills/README.md

@@ -0,0 +1,55 @@
+# Skill Library — SOLUTION_ERP
+
+Skill này là tài liệu chuyên biệt để Claude (và developer khác) dùng khi cần deep-dive 1 domain area. Claude tự động invoke qua Skill tool dựa trên semantic matching với `description` trong từng `SKILL.md`.
+
+## Skills hiện có
+
+| Skill | Mục đích | Trigger ví dụ | Trạng thái |
+|---|---|---|---|
+| `contract-workflow` | State machine 9 phase, role × phase guard, SLA timer, auto-approve | "approve contract", "chuyển phase", "auto-approve quá hạn" | 📝 Placeholder (Phase 3) |
+| `form-engine` | Render template docx/xlsx, parse 8 form, field mapping, PO generator | "export contract as word", "điền form", "render template" | 📝 Placeholder (Phase 2) |
+| `permission-matrix` | Role × MenuKey × CRUD, seed, reset password, 3-layer resolution | "permission denied", "gán role", "menu không hiện" | 📝 Placeholder (Phase 1) |
+
+## Format chuẩn 1 skill
+
+Mỗi skill là 1 folder với ít nhất `SKILL.md` + optional `examples/` + `references/`:
+
+```
+.claude/skills/<skill-name>/
+├── SKILL.md                  ← Entry point: description, when-to-use, workflow
+├── examples/                 ← Code snippets mẫu
+│   └── *.cs | *.tsx
+└── references/               ← Link đến file code thật, docs
+```
+
+**Frontmatter `SKILL.md`:**
+
+```markdown
+---
+name: contract-workflow
+description: State machine 9 phase cho hợp đồng — guard rule, SLA, auto-approve
+when-to-use:
+  - "approve contract"
+  - "state machine bug"
+  - "SLA expired"
+---
+
+# Contract Workflow Skill
+
+## Context
+...
+
+## Workflow
+...
+
+## Code pointers
+- `src/Backend/SolutionErp.Domain/Contracts/ContractPhase.cs`
+- `src/Backend/SolutionErp.Application/Contracts/Commands/TransitionContractCommand.cs`
+```
+
+## Tạo skill mới — checklist
+
+1. Tạo folder `.claude/skills/<kebab-case-name>/`
+2. Viết `SKILL.md` với frontmatter + sections: Context / Workflow / Code pointers / Common pitfalls
+3. Add row vào bảng "Skills hiện có" phía trên
+4. Commit `[CLAUDE] Skill: add <name>`