[CLAUDE] AwV2: Mig 25 +IsUserSelectable + Designer pin toggle + Workspace filter, bỏ "(clone)"

Hai yêu cầu UAT 2026-05-08:
1. Bỏ "(clone)" auto-append khi clone version mới — version đã đủ phân biệt.
2. Thêm pin toggle để admin chọn workflows nào cho user pick lúc tạo phiếu.

Migration 25 AddIsUserSelectableToApprovalWorkflows:
- ALTER ApprovalWorkflows ADD IsUserSelectable bit NOT NULL DEFAULT 0
- UPDATE backfill SET IsUserSelectable=1 WHERE IsActive=1 (giữ behavior cũ
  cho active versions, archived = false default — admin tự pin nếu cần)

BE:
- Domain ApprovalWorkflow +property IsUserSelectable
- DTO AwDefinitionDto +field
- CreateAwDefinitionCommandHandler set default true cho version mới
- New SetAwUserSelectableCommand + Handler
- API PATCH /api/approval-workflows-v2/{id}/user-selectable (Workflows.Create policy)
- DbInitializer SeedSampleApprovalWorkflowsV2Async set IsUserSelectable=true

FE Designer (fe-admin):
- DefinitionDto +isUserSelectable
- Badge amber "Pin Cho user chọn" khi true (cạnh Đang áp dụng/Archived)
- Button "Pin/PinOff Ghim cho user / Bỏ ghim" trong action group + mutation toggle
- Auto-fill name khi clone: bỏ "(clone)" suffix → giữ nguyên name

FE Workspace (fe-admin + fe-user):
- approvalWorkflows query filter w.isUserSelectable === true
- User dropdown chỉ thấy workflows admin đã pin

Verify: dotnet build pass · 81 test pass · npm build × 2 pass · Mig 25 apply LocalDB OK.

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

src/Backend/SolutionErp.Api/Controllers/ApprovalWorkflowsV2Controller.cs

@@ -32,6 +32,17 @@ public class ApprovalWorkflowsV2Controller(IMediator mediator) : ControllerBase
         return Ok(new { id });
     }
 
+    public record SetUserSelectableBody(bool IsUserSelectable);
+
+    // Mig 25 — admin toggle stick/unstick "cho user pick lúc create phiếu".
+    [HttpPatch("{id:guid}/user-selectable")]
+    [Authorize(Policy = "Workflows.Create")]
+    public async Task<IActionResult> SetUserSelectable(Guid id, [FromBody] SetUserSelectableBody body, CancellationToken ct)
+    {
+        await mediator.Send(new SetAwUserSelectableCommand(id, body.IsUserSelectable), ct);
+        return NoContent();
+    }
+
     [HttpDelete("{id:guid}")]
     [Authorize(Policy = "Workflows.Create")]
     public async Task<IActionResult> Delete(Guid id, CancellationToken ct)