[CLAUDE] Domain+Infra+App+FE: dynamic workflow policy per ContractType

Đọc QT-TP-NCC.docx: quy trình 9 bước chỉ áp dụng cho Thầu phụ/NCC/Tổ đội.
Dịch vụ/Mua bán/Nguyên tắc bypass CCM. Thay hardcoded dict bằng policy
registry.

Domain — WorkflowPolicy.cs:
- Record WorkflowPolicy { Name, Description, Transitions, PhaseSla,
  ActivePhases } — pure data, testable.
- WorkflowPolicies.Standard: 9-phase full (Thầu phụ/Giao khoán/NCC)
- WorkflowPolicies.SkipCcm: 7-phase (Dịch vụ/Mua bán/Nguyên tắc)
- WorkflowPolicyRegistry.For(type) map ContractType → policy
- WorkflowPolicyRegistry.ForContract(c) override nếu BypassProcurement
  AndCCM=true (instance-level escape hatch)

Infrastructure — ContractWorkflowService:
- Xóa hardcoded Transitions/PhaseSla dicts → load từ policy.ForContract
- TransitionAsync: validate qua policy.Transitions thay vì dict local
- Error message include policy.Name để debug dễ hơn
- GetPhaseSla trả SLA từ Standard policy (fallback — SLA hiện tại giống
  nhau giữa 2 policy)

Application — ContractDetailDto:
- Field mới `Workflow: WorkflowSummaryDto { PolicyName, Description,
  ActivePhases, NextPhases }` — FE dùng để render nút chuyển phase
  dynamic + timeline card.
- BuildWorkflowSummary helper trong ContractFeatures.

FE (both apps):
- Type WorkflowSummary + ContractDetail.workflow
- ContractDetailPage xóa hardcoded NEXT_PHASES — dùng
  c.workflow.nextPhases từ BE (single source of truth)
- WorkflowSummaryCard: timeline của ActivePhases với check/current/
  future states + policy name/description ở header
- Card hiển thị trong sidebar, phía trên "Lịch sử duyệt"

Docs:
- gotchas.md #21 marked RESOLVED (NEXT_PHASES sync không còn cần)

Foundation: sau này admin có thể edit policy qua UI khi chuyển sang DB-
backed policy — nhưng API contract (WorkflowSummaryDto) đã stable.

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

src/Backend/SolutionErp.Application/Contracts/ContractFeatures.cs

@@ -375,7 +375,20 @@ public class GetContractQueryHandler(
                 .Select(att => new ContractAttachmentDto(
                     att.Id, att.FileName, att.StoragePath, att.FileSize,
                     att.ContentType, att.Purpose, att.Note, att.CreatedAt))
-                .ToList());
+                .ToList(),
+            BuildWorkflowSummary(c));
+    }
+
+    // FE uses this to render next-phase buttons dynamically — no more hardcoded
+    // NEXT_PHASES map that silently drifts from the BE policy.
+    private static WorkflowSummaryDto BuildWorkflowSummary(Contract c)
+    {
+        var policy = WorkflowPolicyRegistry.ForContract(c);
+        return new WorkflowSummaryDto(
+            PolicyName: policy.Name,
+            PolicyDescription: policy.Description,
+            ActivePhases: policy.ActivePhases.ToList(),
+            NextPhases: policy.NextPhasesFrom(c.Phase).ToList());
     }
 }
 

src/Backend/SolutionErp.Application/Contracts/Dtos/ContractDtos.cs

@@ -40,7 +40,16 @@ public record ContractDetailDto(
     DateTime? UpdatedAt,
     List<ContractApprovalDto> Approvals,
     List<ContractCommentDto> Comments,
-    List<ContractAttachmentDto> Attachments);
+    List<ContractAttachmentDto> Attachments,
+    WorkflowSummaryDto Workflow);
+
+// Policy snapshot for the FE — lets UI render next-phase buttons dynamically
+// without hardcoding the transition map (single source of truth in BE).
+public record WorkflowSummaryDto(
+    string PolicyName,
+    string PolicyDescription,
+    List<ContractPhase> ActivePhases,
+    List<ContractPhase> NextPhases);
 
 public record ContractApprovalDto(
     Guid Id,