[CLAUDE] Move nested-type menu → fe-user; Admin workflow config page

User clarified: menu loại HĐ 3-level (Danh sách/Thao tác/Duyệt) thuộc
fe-user. Admin có page riêng để config quy trình per loại HĐ.

fe-admin Layout:
- filterForAdmin() drops Ct_* entries (hide nested type menu).
- Admin sidebar giờ về lại đơn giản: Dashboard / Master / Hợp đồng
  (leaf) / Forms / Reports / System.

fe-user Layout:
- Dynamic menu tree từ /menus/me (thay fixed USER_MENU hardcoded).
- Recursive MenuNodeRenderer (top-level expanded, nested collapsed).
- resolvePath user-specific: Ct_*_List → /my-contracts?type=X,
  Ct_*_Create → /contracts/new?type=X, Ct_*_Pending → /inbox?type=X.
- filterForUser drops admin-only entries (Master/System/Forms/Reports).
- Static USER_FIXED_TOP prepends "Hộp thư" leaf → /inbox.
- MyContractsPage + InboxPage đọc ?type=X param, filter client-side.

Workflow config (Admin side):
- Domain: WorkflowTypeAssignment entity (ContractType → PolicyName
  override). Registry.ForContractWithOverrides() prefer DB override
  else default.
- Infrastructure: EF config + migration AddWorkflowTypeAssignments,
  unique index trên ContractType. ContractWorkflowService load
  overrides dict mỗi transition. ContractFeatures load overrides khi
  build WorkflowSummaryDto.
- Application: GetWorkflowAdminOverviewQuery returns 7 types × current
  policy + available policies. SetWorkflowAssignmentCommand validate
  policy name tồn tại; nếu = default thì delete override (no stale row).
- Api: GET /api/workflows + PUT /api/workflows/{contractType}
  với policy "Workflows.Read" + "Workflows.Update".
- Menu: new key `Workflows` dưới System, label "Quy trình HĐ".
- FE /system/workflows: 7 card per type, dropdown Standard/SkipCcm +
  'Đã override' badge khi khác default, phase sequence timeline,
  explanation banner ở top. Iteration 2 note: admin-authored custom
  policies.

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

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

@@ -0,0 +1,27 @@
+using MediatR;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using SolutionErp.Application.Contracts;
+using SolutionErp.Domain.Contracts;
+
+namespace SolutionErp.Api.Controllers;
+
+[ApiController]
+[Route("api/workflows")]
+[Authorize(Policy = "Workflows.Read")]
+public class WorkflowsController(IMediator mediator) : ControllerBase
+{
+    [HttpGet]
+    public async Task<ActionResult<WorkflowAdminOverviewDto>> Overview(CancellationToken ct)
+        => Ok(await mediator.Send(new GetWorkflowAdminOverviewQuery(), ct));
+
+    [HttpPut("{contractType:int}")]
+    [Authorize(Policy = "Workflows.Update")]
+    public async Task<IActionResult> SetAssignment(int contractType, [FromBody] SetWorkflowAssignmentBody body, CancellationToken ct)
+    {
+        await mediator.Send(new SetWorkflowAssignmentCommand((ContractType)contractType, body.PolicyName), ct);
+        return NoContent();
+    }
+}
+
+public record SetWorkflowAssignmentBody(string PolicyName);