[CLAUDE] App+Api+FE-User+FE-Admin+Tests: W2 KHKK — CRUD phieu nhap + can cu b.8-9 + FE 3 page x2 app + 12 fix reviewer

- BE mega-file ContractSigningPlanFeatures (Create 4-rao + auto-Lines snapshot per-winner + MaKeHoach @CREATE + UpdateDraft null-safe + Get/List/inbox-precompute-V2/deleted + Dossier + Attachments + Delete allow-list M6 + picker) + Controller 15 action policy per-action 15/15 (KeHoachKyKet.*)
- FE pages/khkk 3 page + types x2 app SHA-pair + 4-place (6 leaf Khkk_* het coming-soon; WfView: user=matrix?type=10 [whitelist +10] / admin=Designer deep-link); root KeHoachKyKet -> /khkk/list
- Reviewer adversarial: 12 finding (3 CRITICAL dut-2-bo FE-BE: route picker + peId body + dossier planId; 2 MAJOR security: detail+download 0 rao -> EnsureCanViewAsync mirror PE S89 nhap-rieng-tu; PUT-vs-POST de-ban-sao; peTenGoiThau; winnerSupplierNames; Content-Disposition RFC6266; LEFT-join Projects) -> 11 FIXED + 1 GIU (F-10 ke thua khuon PE, bit dong bo sau)
- tests: +8 (574 total 0 fail) — authz reflection dong + Create/Delete/guard/khong-dot-ma-khi-409 + fixture-co-interceptor

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Backend/SolutionErp.Application/ContractSigningPlans/Services/IContractSigningPlanCodeGenerator.cs

@@ -6,7 +6,9 @@ namespace SolutionErp.Application.ContractSigningPlans.Services;
 //   - Sequence per-năm qua bảng WorkflowAppCodeSequences DÙNG CHUNG (per-prefix row,
 //     IApplicationDbContext) — KHÔNG bảng sequence riêng (spec W1 §②-9, #8-CẮT spec cũ).
 //   - Seq reset đầu năm tự nhiên (key Prefix "KHKK/{YYYY}" mới).
-// Caller: W2 Submit (gen lúc trình duyệt, KHÔNG lúc tạo nháp — mirror quyết spec cũ).
+// Caller: W2 `CreateContractSigningPlanCommandHandler` — gen NGAY LÚC TẠO phiếu.
+// 🔴 Đính chính bản W1 ("gen lúc Submit"): spec W2 §③-B đòi POST trả `maKeHoach` khớp
+// `^KHKK/\d{4}/\d{3}$` ⇒ mã phải có từ lúc tạo, không defer tới trình duyệt.
 public interface IContractSigningPlanCodeGenerator
 {
     // Gen mã atomic — transaction SERIALIZABLE chống race (mirror PE/Contract codegen).