[CLAUDE] Phase4: Report MVP + Docs Consolidation (rules, architecture, schema-diagram)

Backend Report:
- Application/Reports/Dtos/DashboardStatsDto: 5 KPI + PhaseCount + SupplierCount + ProjectCount + MonthlyValue
- Application/Reports/Queries/GetDashboardStats handler: total/active/overdue/published this month/totalValueActive + byPhase + top 5 NCC/du an + 12 thang monthly (fill zero khi thang empty)
- Application/Reports/Services/IContractExcelExporter interface
- Infrastructure/Reports/ContractExcelExporter: ClosedXML workbook 10 cot, header style bold+blue, number format #,##0, formula SUM, auto-fit, freeze header
- Application/Reports/Commands/ExportContractsToExcelCommand: filter phase/supplier/project/date range
- Api/Controllers/ReportsController: GET /reports/dashboard, GET /reports/contracts/export
- DI register IContractExcelExporter (Scoped)

Frontend fe-admin:
- types/reports.ts: DashboardStats type
- components/BarChart.tsx: generic horizontal bar chart — chi Tailwind, khong thu vien ngoai
- pages/DashboardPage.tsx REWRITE: 5 KPI card (FileText/TrendingUp/AlertTriangle/CheckCircle2/Coins) + by-phase bar + monthly 12-month chart + top 5 NCC + top 5 du an + skeleton loader
- pages/ReportsPage.tsx MOI: filter phase/fromDate/toDate → export Excel button
- Route /reports vao App.tsx

E2E verified:
- GET /api/reports/dashboard → 200 voi day du KPI + monthly fill 12 thang
- GET /api/reports/contracts/export → 200 xlsx 7229 bytes (Microsoft Excel 2007+)

Docs consolidation (theo yeu cau user):
- docs/rules.md MOI: 9 section coding conventions (ngon ngu UI/code/DB/docs, BE Clean Arch, CQRS+MediatR, Validation FluentValidation, Error handling, Async, Entity rules, DI, Package pinning, FE React/TS erasableSyntaxOnly, path alias, TanStack Query, Permission guard, Toast+error, DB convention, Git commit format, Docs structure, Testing, Security)
- docs/architecture.md MOI: layered overview ASCII art, request lifecycle (1 POST/api/contracts qua 10 step), workflow state machine 9 phase, permission model, data flow sequence diagram 4 actor (Drafter/Manager/CCM/BOD/HRA), deployment architecture Phase 5, skill library, non-functional table
- docs/database/schema-diagram.md MOI: full ERD 19 table mermaid + data flow diagram + vong doi 1 HD (create → 7 transition → gen ma → publish) + index strategy table + relationship cardinality + soft delete behavior + SQL queries (inbox/dashboard/gen ma) + migration history
- docs/gotchas.md UPDATE: 17 → 26 pitfalls, them section "Claude Code harness quirks" (Edit File not read, DI build pass nhung runtime fail) + "Contract workflow" (ma HD gen 2 lan, BE-FE NEXT_PHASES sync, race condition) + "Permission matrix" (cache real-time, MenuKey typo)
- docs/STATUS.md: Phase 4 MVP done, docs entry points section liet ke het, next Phase 5 Production
- docs/HANDOFF.md: phase table them Phase 4 row, file tree update voi Reports, test points day du, git state commit 7
- docs/changelog/migration-todos.md: tick Phase 4 MVP items + them iteration 2 list
- docs/changelog/sessions/2026-04-21-1430-phase4-report.md: session log voi thong so cumulative (BE 3100 LOC, 30 docs)
- CLAUDE.md root: update Tai lieu quan trong section them rules.md, architecture.md, schema-diagram.md, .claude/skills (13 links now)

Bug fix:
- TS unused import ContractPhaseLabel trong DashboardPage
- DI thieu register IContractExcelExporter — build pass but runtime would fail (added)

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

docs/changelog/migration-todos.md

@@ -158,13 +158,25 @@
 
 ## Phase 4 — Reporting + Polish (T10-11)
 
-- [ ] Dashboard admin: số HĐ theo phase, top NCC, top dự án, tổng giá trị theo tháng
-- [ ] Excel export theo bộ lọc (dùng EPPlus)
-- [ ] Report: HĐ quá hạn SLA bao nhiêu lần theo phase/role
-- [ ] UX polish: skeleton loader, empty state, error boundary có recovery button
+### MVP xong (iteration 1)
+
+- [x] Dashboard admin: 5 KPI (total/active/overdue/published this month/total value) + by phase + top 5 NCC + top 5 dự án + 12 tháng
+- [x] Excel export HĐ theo filter (phase/supplier/project/date range) qua ClosedXML
+- [x] BE `GetDashboardStatsQuery` + `ExportContractsToExcelCommand` + ReportsController
+- [x] FE `DashboardPage` rewrite với `BarChart` tự build (Tailwind only, không thư viện ngoài)
+- [x] FE `ReportsPage` filter + export
+- [x] Docs consolidation: `rules.md` + `architecture.md` + `database/schema-diagram.md` + gotchas update
+
+### Iteration 2 (polish — optional)
+
+- [ ] SLA overdue report (by role / phase, export Excel)
+- [ ] Contract audit log export (từng HĐ ra PDF)
+- [ ] Dashboard user-specific (HĐ của tôi / role của tôi)
+- [ ] Chart library recharts (nếu cần chart phức tạp)
+- [ ] UX polish: skeleton loader cho mọi list, empty state có action, error boundary recovery
 - [ ] Accessibility: keyboard nav, focus trap modal, aria labels
-- [ ] Dark mode (optional, nếu rảnh)
-- [ ] Performance: index DB cho query hot (SupplierId, ProjectId, Phase)
+- [ ] Dark mode
+- [ ] Performance: explicit index DB cho query hot đã identify
 - [ ] Tài liệu user guide: quy trình tạo HĐ + duyệt
 - [ ] UAT với 5-10 HĐ dữ liệu thật từ bộ phận Cung ứng