[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>

src/Backend/SolutionErp.Api/Controllers/ReportsController.cs

@@ -0,0 +1,32 @@
+using MediatR;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using SolutionErp.Application.Reports.Commands.ExportContractsToExcel;
+using SolutionErp.Application.Reports.Dtos;
+using SolutionErp.Application.Reports.Queries.GetDashboardStats;
+using SolutionErp.Domain.Contracts;
+
+namespace SolutionErp.Api.Controllers;
+
+[ApiController]
+[Route("api/reports")]
+[Authorize]
+public class ReportsController(IMediator mediator) : ControllerBase
+{
+    [HttpGet("dashboard")]
+    public async Task<ActionResult<DashboardStatsDto>> Dashboard(CancellationToken ct)
+        => Ok(await mediator.Send(new GetDashboardStatsQuery(), ct));
+
+    [HttpGet("contracts/export")]
+    public async Task<IActionResult> ExportContracts(
+        [FromQuery] ContractPhase? phase,
+        [FromQuery] Guid? supplierId,
+        [FromQuery] Guid? projectId,
+        [FromQuery] DateTime? fromDate,
+        [FromQuery] DateTime? toDate,
+        CancellationToken ct)
+    {
+        var result = await mediator.Send(new ExportContractsToExcelCommand(phase, supplierId, projectId, fromDate, toDate), ct);
+        return File(result.Content, result.ContentType, result.FileName);
+    }
+}