[CLAUDE] PurchaseEvaluation: multi-NCC per hạng mục — chọn ≥2 NCC-TP trúng thầu/1 hạng mục (mỗi nhà 1 giá riêng)

Đổi winner-truth từ whole-supplier Supplier.IsWinner (Mig 58 liên-danh) sang per-hạng-mục
Quote.IsSelected (Mig 12 dormant hook → nay nguồn-sự-thật); Supplier.IsWinner = DERIVED (== Any IsSelected).
Anh Kiệt LOCKED D1=SUM(IsSelected) · D2=THAY-THẾ · D3=giá-chào-gốc · D4=1HĐ/NCC. 0 bảng/cột mới.

BE:
- SelectWinnerCommand + POST /select-winner: body {supplierIds} → {detailId, supplierIds} (per hạng mục).
- Re-key 5 financial-SUM → WHERE IsSelected: winnerQuoteTotal, submit-guard, CCM-threshold, giaTri, budget-B.
- giaTri bỏ shortcut isSingle→detailsSum (single đổi budget→bid theo D4).
- Derive IsWinner invariant ở MỌI writer: SelectWinner + UpsertQuote + seed + DeleteQuote/DeleteDetail (helper PeWinnerInvariant, fix Bước 4).
- GIỮ IsWinner-derived cho winner-names/existence + CreateContract winners-list.
- Migration BackfillPeQuoteIsSelectedAndWinnerInvariant (data-only 2-chiều IsWinner↔IsSelected, Down no-op).

FE 2-app (PeDetailTabs SHA-identical): HangMucCard per-cell winner grid Detail×NCC + toggle per-detail; NccSelectorRow hạ-cấp read-only summary; giữ derived display.

Test: 7 file update + 8 test mới (per-hạng-mục total, giaTri single-partial, threshold-crossing, derive-invariant, delete-path). 486 PASS.

Flow: fable-clone invest ensemble → anh Kiệt 4-decision → fable-clone review ensemble (6 adjustment) → hmw implement (disk-recover #53) → fable-clone verify (bắt MUST bug delete-path → fix test-before).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/SolutionErp.Infrastructure.Tests/Application/CreateContractFromEvaluationMultiWinnerTests.cs

@@ -64,6 +64,11 @@ public class CreateContractFromEvaluationMultiWinnerTests
     // Seed 1 PE (default DaDuyet) + N supplier rows; winnersByIndex marks which supplier-rows
     // are IsWinner. detailQuotes[i][j] = ThanhTien báo giá của supplier j cho detail i.
     // detailBudgets[i] = ThanhTienNganSach (ngân sách) của detail i.
+    // [multi-NCC 2026-07-12 cardinality-change] GiaTri mỗi HĐ NAY = SUM ThanhTien quote ĐƯỢC CHỌN
+    // (Quote.IsSelected) của winner đó — CreateContractFromEvaluationFeatures.cs:88-90
+    // `q.PurchaseEvaluationSupplierId == w.Id && q.IsSelected`. Nên quote của winner PHẢI
+    // IsSelected=true mới cộng vào GiaTri. detailQuoteSelected[i][j] override IsSelected per
+    // (detail,supplier); null → mặc định winner's-all-selected (IsSelected = winnerIndexes.Contains(j)).
     private static async Task<Seeded> SeedAsync(
         IdentityFixture fix,
         TestApplicationDbContext db,
@@ -71,7 +76,8 @@ public class CreateContractFromEvaluationMultiWinnerTests
         int[] winnerIndexes,
         decimal[] detailBudgets,
         decimal[][] detailQuotes,
-        PurchaseEvaluationPhase phase = PurchaseEvaluationPhase.DaDuyet)
+        PurchaseEvaluationPhase phase = PurchaseEvaluationPhase.DaDuyet,
+        bool[][]? detailQuoteSelected = null)
     {
         var actor = await fix.CreateUserAsync("drafter-d2@test.local", "Drafter D2",
             departmentId: null, roles: new[] { AppRoles.Drafter });
@@ -136,12 +142,16 @@ public class CreateContractFromEvaluationMultiWinnerTests
             // Quote per supplier cho detail này — FK PESupplierId → supplier-row.Id.
             for (var j = 0; j < supplierCount; j++)
             {
+                var isSelected = detailQuoteSelected is not null
+                    ? detailQuoteSelected[i][j]
+                    : winnerIndexes.Contains(j);   // mặc định: quote của winner = được chọn
                 detail.Quotes.Add(new PurchaseEvaluationQuote
                 {
                     Id = Guid.NewGuid(),
                     PurchaseEvaluationDetailId = detail.Id,
                     PurchaseEvaluationSupplierId = suppliers[j].Item2.Id,
                     ThanhTien = detailQuotes[i][j],
+                    IsSelected = isSelected,
                 });
             }
             pe.Details.Add(detail);
@@ -206,16 +216,19 @@ public class CreateContractFromEvaluationMultiWinnerTests
         peReloaded.ContractId.Should().Be(ids[0]);
     }
 
-    // ===== (b) single winner → 1 HĐ, GiaTri = details budget sum (LEGACY preserved) =====
+    // ===== single winner → 1 HĐ, GiaTri = SUM báo giá ĐƯỢC CHỌN của winner (D4) =====
+    // [multi-NCC 2026-07-12 — SPEC CHANGE D4] BỎ shortcut detailsSum (budget) cũ cho single.
+    // NAY single = SUM(Quote.IsSelected của winner), giống multi. Trước đây test này assert
+    // GiaTri = 800 (budget sum); giờ = 140 (100+40 = quote ĐƯỢC CHỌN của winner0).
 
     [Fact]
-    public async Task Create_SingleWinner_GiaTriIsDetailsBudgetSum_NotQuoteTotal()
+    public async Task Create_SingleWinner_GiaTriIsSelectedQuoteTotal_NotBudgetSum()
     {
         using var fix = new IdentityFixture();
         var db = fix.Services.GetRequiredService<TestApplicationDbContext>();
 
-        // 1 winner (idx 0). detailBudgets sum = 500 + 300 = 800. winner0 quote total =
-        // 100 + 40 = 140. Single-winner PHẢI = 800 (budget), KHÔNG = 140 (quote).
+        // 1 winner (idx 0). detailBudgets sum = 500 + 300 = 800 (KHÔNG dùng nữa). winner0 quote
+        // ĐƯỢC CHỌN = 100 + 40 = 140. Single-winner NAY = 140 (quote IsSelected), KHÔNG = 800 (budget).
         var seeded = await SeedAsync(fix, db,
             supplierCount: 2,
             winnerIndexes: new[] { 0 },
@@ -235,7 +248,7 @@ public class CreateContractFromEvaluationMultiWinnerTests
 
         var contract = await db.Contracts.AsNoTracking().FirstAsync(c => c.Id == ids[0]);
         contract.SupplierId.Should().Be(seeded.Suppliers[0].supplier.Id);
-        contract.GiaTri.Should().Be(800m);                       // LEGACY: budget sum, NOT 140
+        contract.GiaTri.Should().Be(140m, "D4: single-winner = SUM báo giá ĐƯỢC CHỌN (100+40), KHÔNG phải budget 800");
         contract.Phase.Should().Be(ContractPhase.DangSoanThao);
         contract.MaHopDong.Should().NotBeNull();
         // TenHopDong null trong request → fallback pe.TenGoiThau.
@@ -245,6 +258,45 @@ public class CreateContractFromEvaluationMultiWinnerTests
         peReloaded.ContractId.Should().Be(ids[0]);
     }
 
+    // ===== (b) [multi-NCC 2026-07-12 — NEW] single-winner thắng SUBSET hạng mục =====
+    // Winner thắng CHỈ 1 trong 2 hạng mục (detail0 IsSelected=true, detail1 IsSelected=false)
+    // → GiaTri = SUM(selected quotes) = quote detail0 THÔI, KHÁC SUM-mọi-quote-của-winner
+    // (chống bug detailsSum/all-quote cũ). Chứng minh handler lọc theo Quote.IsSelected per hạng mục.
+    [Fact]
+    public async Task Create_SingleWinner_WinsSubsetOfDetails_GiaTriSumsOnlySelectedQuotes()
+    {
+        using var fix = new IdentityFixture();
+        var db = fix.Services.GetRequiredService<TestApplicationDbContext>();
+
+        // Winner = supplier0. detail0 quote 300 ĐƯỢC CHỌN, detail1 quote 500 KHÔNG chọn.
+        // GiaTri = 300 (chỉ selected); SUM-mọi-quote-winner = 800; budget-sum = 2000. Cả 3 khác nhau.
+        var seeded = await SeedAsync(fix, db,
+            supplierCount: 2,
+            winnerIndexes: new[] { 0 },
+            detailBudgets: new[] { 1000m, 1000m },              // sum 2000 — KHÔNG dùng
+            detailQuotes: new[]
+            {
+                new[] { 300m, 11m },                            // detail0: winner0=300
+                new[] { 500m, 13m },                            // detail1: winner0=500 (KHÔNG chọn)
+            },
+            detailQuoteSelected: new[]
+            {
+                new[] { true, false },                          // detail0: winner0 ĐƯỢC CHỌN
+                new[] { false, false },                         // detail1: winner0 KHÔNG chọn
+            });
+        var handler = BuildHandler(db, fix.Services, seeded.Actor);
+
+        var ids = await handler.Handle(
+            new CreateContractFromEvaluationCommand(seeded.Pe.Id, ContractType.HopDongThauPhu, null),
+            CancellationToken.None);
+
+        ids.Should().HaveCount(1);
+        var contract = await db.Contracts.AsNoTracking().FirstAsync(c => c.Id == ids[0]);
+        contract.SupplierId.Should().Be(seeded.Suppliers[0].supplier.Id);
+        contract.GiaTri.Should().Be(300m,
+            "SUM chỉ quote ĐƯỢC CHỌN (detail0=300); KHÁC SUM-mọi-quote-winner (800) + budget-sum (2000)");
+    }
+
     // ===== (c) idempotency → re-call throws ConflictException =====
 
     [Fact]

tests/SolutionErp.Infrastructure.Tests/Application/PeListWinnerNamesProjectionTests.cs

@@ -20,6 +20,12 @@ namespace SolutionErp.Infrastructure.Tests.Application;
 // NẾU EF KHÔNG translate (runtime InvalidOperationException) → test FAIL = blocker
 // REPORT em main (fallback 2-pass). Dùng SqliteDbFixture (KHÔNG cần Identity — query
 // chỉ đọc, DrafterUserId LEFT-join Users nullable).
+//
+// [multi-NCC 2026-07-12 cardinality-change] Winner-truth chuyển whole-supplier IsWinner →
+// per-(Detail×Supplier) Quote.IsSelected; NHƯNG Supplier.IsWinner GIỮ là cột PERSISTED
+// (BE tự derive = Any quote IsSelected trong SelectWinner/UpsertQuote handler). WinnerSupplierNames
+// projection ĐỌC THẲNG cột IsWinner đã persist (`where sw.IsWinner`) → KHÔNG đổi theo cardinality.
+// Seed IsWinner trực tiếp = hợp lệ cho translation-smoke (không cần seed quote — projection không đọc quote).
 public class PeListWinnerNamesProjectionTests
 {
     private static (Project project, Supplier[] suppliers) SeedMasters(TestApplicationDbContext db, int supplierCount)

tests/SolutionErp.Infrastructure.Tests/Application/PeMultiWinnerTests.cs

@@ -72,7 +72,11 @@ public class PeMultiWinnerTests
     }
 
     // 1 NCC tham gia (master + PES row) + 1 quote ThanhTien thuộc detail. isWinner pin
-    // IsWinner trên PES row. Return supplierId master.
+    // IsWinner trên PES row VÀ IsSelected trên quote (invariant IsWinner==Any(IsSelected)).
+    // [multi-NCC 2026-07-12 cardinality-change] DTO WinnerQuoteTotal NAY = SUM ThanhTien
+    // quote ĐƯỢC CHỌN (Quote.IsSelected — PurchaseEvaluationFeatures.cs:1188-1191
+    // `.Where(q => q.IsSelected)`), KHÔNG còn build từ IsWinner supplier-row. Nên winner PHẢI
+    // có quote.IsSelected=true thì mới lọt tổng; loser IsSelected=false → bị loại. Return supplierId.
     private static async Task<Guid> SeedSupplierWithQuoteAsync(
         TestApplicationDbContext db, PurchaseEvaluation pe, Guid detailId,
         string code, decimal thanhTien, bool isWinner, int order)
@@ -94,6 +98,7 @@ public class PeMultiWinnerTests
             PurchaseEvaluationDetailId = detailId,
             PurchaseEvaluationSupplierId = pes.Id,
             ThanhTien = thanhTien,
+            IsSelected = isWinner,   // [multi-NCC] winner ⟺ báo giá được chọn
         });
         await db.SaveChangesAsync(CancellationToken.None);
         return supplier.Id;
@@ -215,11 +220,13 @@ public class PeMultiWinnerTests
         {
             Id = Guid.NewGuid(), PurchaseEvaluationDetailId = detail1,
             PurchaseEvaluationSupplierId = pes.Id, ThanhTien = 20_000_000m,
+            IsSelected = true,   // [multi-NCC] cả 2 dòng của winner ĐƯỢC CHỌN → vào tổng
         });
         db.PurchaseEvaluationQuotes.Add(new PurchaseEvaluationQuote
         {
             Id = Guid.NewGuid(), PurchaseEvaluationDetailId = detail2.Id,
             PurchaseEvaluationSupplierId = pes.Id, ThanhTien = 30_000_000m,
+            IsSelected = true,
         });
         await db.SaveChangesAsync(CancellationToken.None);
 
@@ -228,4 +235,35 @@ public class PeMultiWinnerTests
 
         bundle.WinnerQuoteTotal.Should().Be(50_000_000m, "SUM mọi dòng báo giá của winner-row qua nhiều detail");
     }
+
+    // ===== [multi-NCC 2026-07-12 cardinality-change — NEW test (a)] =====
+    // ≥2 NCC/TP cùng trúng TRÊN CÙNG 1 HẠNG MỤC (Detail) — mỗi nhà 1 giá riêng (Quote.ThanhTien).
+    // winnerQuoteTotal = SUM 2 quote IsSelected CỦA hạng mục đó; NCC thứ 3 chào cùng hạng mục
+    // nhưng KHÔNG được chọn (IsSelected=false) → bị loại. Đây là trục cardinality-change cốt lõi:
+    // winner-truth = per-(Detail×Supplier) Quote.IsSelected, KHÔNG phải whole-supplier.
+    [Fact]
+    public async Task WinnerQuoteTotal_TwoNccSameDetail_SumsBothSelected_ExcludesUnselectedThird()
+    {
+        using var fix = new IdentityFixture();
+        var db = fix.Services.GetRequiredService<TestApplicationDbContext>();
+        var pe = await SeedPeAsync(db, "PE-MW-2NCC1HM");
+        var detailId = await SeedDetailAsync(db, pe);   // 1 hạng mục dùng chung 3 NCC
+
+        // 3 NCC chào CÙNG hạng mục detailId: 2 được chọn (33 + 27) + 1 không chọn (50).
+        await SeedSupplierWithQuoteAsync(db, pe, detailId, "NCC-P1", 33_000_000m, isWinner: true, order: 0);
+        await SeedSupplierWithQuoteAsync(db, pe, detailId, "NCC-P2", 27_000_000m, isWinner: true, order: 1);
+        await SeedSupplierWithQuoteAsync(db, pe, detailId, "NCC-P3", 50_000_000m, isWinner: false, order: 2);
+
+        var handler = BuildQueryHandler(fix, db, AsRoles(AppRoles.Admin));
+        var bundle = await handler.Handle(new GetPurchaseEvaluationQuery(pe.Id), CancellationToken.None);
+
+        bundle.WinnerQuoteTotal.Should().Be(60_000_000m,
+            "≥2 NCC trúng CÙNG 1 hạng mục → SUM 2 quote ĐƯỢC CHỌN (33+27); NCC thứ 3 không chọn bị loại");
+        bundle.SelectedSupplierId.Should().BeNull("≥2 đơn vị cùng trúng → không có 1 winner duy nhất");
+
+        // Quote của NCC thứ 3 tồn tại nhưng IsSelected=false → chứng minh loại theo IsSelected.
+        var detailDto = bundle.Details.Single(d => d.Id == detailId);
+        detailDto.Quotes.Should().HaveCount(3, "cả 3 NCC đều có báo giá cho hạng mục");
+        detailDto.Quotes.Count(q => q.IsSelected).Should().Be(2, "đúng 2 báo giá được chọn");
+    }
 }

tests/SolutionErp.Infrastructure.Tests/Application/PeSelectWinnerClearTests.cs

@@ -10,26 +10,32 @@ using SolutionErp.Infrastructure.Tests.Common;
 
 namespace SolutionErp.Infrastructure.Tests.Application;
 
-// [Mig 58 2026-06-24 — CCM/anh Kiệt FDC — test-after] SelectPurchaseEvaluationWinnerCommand
-// MULTI-WINNER. Command record ĐỔI `(Guid PurchaseEvaluationId, Guid? SupplierId)` →
-// `(Guid PurchaseEvaluationId, IReadOnlyList<Guid> SupplierIds)`.
-// Handler (PurchaseEvaluationDetailFeatures.cs ~404-447):
-//   • Load MỌI supplier-row của phiếu (tracking) → set IsWinner = (row.SupplierId ∈
-//     selectedIds), false phần còn lại. IsWinner trên supplier-row = nguồn-sự-thật mới.
-//   • selectedIds rỗng [] = BỎ CHỌN tất cả (IsWinner=false hết) — thay null cũ (anh Kiệt C5).
-//   • Mỗi id chọn PHẢI thuộc participating-list (PurchaseEvaluationSuppliers) → Conflict.
-//   • Distinct id (FE có thể gửi trùng).
-//   • Sync SelectedSupplierId: đúng 1 winner → đơn vị đó (backward compat luồng tạo HĐ +
-//     DTO cũ); ≥2 HOẶC 0 → null.
-//   • KHÔNG còn check master Suppliers existence (logic mới chỉ validate participating-list)
-//     — NotFound master-existence bỏ; chỉ Conflict khi id không thuộc list của phiếu.
-// Mọi nhánh ghi 1 Changelog (Header/Update) — Summary "Bỏ chọn đơn vị NCC/TP trúng thầu"
-// (count==0) vs "Chọn {n} đơn vị NCC/TP trúng thầu".
+// [multi-NCC 2026-07-12 — anh Kiệt LOCKED — cardinality-change test-before] SelectPurchaseEvaluationWinnerCommand
+// đổi `(Guid PurchaseEvaluationId, IReadOnlyList<Guid> SupplierIds)` → thêm DetailId:
+// `(Guid PurchaseEvaluationId, Guid DetailId, IReadOnlyList<Guid> SupplierIds)`. Winner NAY chọn
+// theo TỪNG HẠNG MỤC (Detail) — mỗi hạng mục ≥2 NCC/TP có thể cùng trúng, mỗi nhà 1 giá riêng.
 //
-// Handler 2-dep (db + ICurrentUser), KHÔNG cần UserManager → SqliteDbFixture đủ nhẹ
-// (mirror DepartmentTreeTests). ICurrentUser fake cứng để Changelog ghi UserId/Name.
+// Handler (PurchaseEvaluationDetailFeatures.cs ~410-480):
+//   • Load PE (NotFound) → Load Detail thuộc PE (NotFound) → Load MỌI supplier-row của phiếu.
+//   • Validate mỗi selected SupplierId ∈ participating-list → Conflict "NCC chưa được thêm vào phiếu".
+//   • Load MỌI quote của phiếu → set Quote.IsSelected cho quotes CỦA DetailId NÀY: true nếu
+//     supplier-row thắng, false còn lại. NGUỒN-SỰ-THẬT = Quote.IsSelected (per Detail×Supplier).
+//   • Derive Supplier.IsWinner (INVARIANT): winner ⟺ có ÍT NHẤT 1 quote IsSelected TOÀN PHIẾU.
+//   • Sync SelectedSupplierId: đúng 1 winner toàn phiếu → đơn vị đó; ≥2 HOẶC 0 → null.
+//   • Changelog Header/Update Summary: count==0 → "Bỏ chọn NCC/TP trúng thầu cho hạng mục {GroupCode}";
+//     else "Chọn {n} NCC/TP trúng thầu cho hạng mục {GroupCode}".
+//
+// ⚠️ CARDINALITY-CHANGE (khác test cũ): IsWinner KHÔNG còn set-thẳng — nó DERIVE từ Quote.IsSelected.
+//   Muốn supplier thành winner qua SelectWinner thì (Detail × Supplier) PHẢI có 1 quote để handler
+//   flip IsSelected → derive IsWinner. Test seed 1 detail + 1 quote/participating-row (helper
+//   AddParticipatingWithQuoteAsync). Test dùng SQLite EnsureCreated — KHÔNG replay migration
+//   backfill (chỉ SQL-Server) → seed IsSelected/IsWinner trực tiếp cho pre-state.
+//
+// Handler 2-dep (db + ICurrentUser) → SqliteDbFixture đủ nhẹ. ICurrentUser fake để Changelog ghi.
 public class PeSelectWinnerClearTests
 {
+    private const string DetailGroupCode = "A.I";
+
     private sealed class FakeCurrentUser : ICurrentUser
     {
         public Guid? UserId { get; init; } = Guid.NewGuid();
@@ -43,6 +49,10 @@ public class PeSelectWinnerClearTests
         TestApplicationDbContext db)
         => new(db, new FakeCurrentUser());
 
+    private static UpsertPurchaseEvaluationQuoteCommandHandler BuildUpsertQuoteHandler(
+        TestApplicationDbContext db)
+        => new(db, new FakeCurrentUser());
+
     private static async Task<Supplier> SeedSupplierAsync(
         TestApplicationDbContext db, string code)
     {
@@ -52,8 +62,8 @@ public class PeSelectWinnerClearTests
         return s;
     }
 
-    // Phiếu PE + (tùy chọn) SelectedSupplierId pre-set. KHÔNG tự thêm participating
-    // row — caller quyết định để cô lập nhánh clear (skip-list) vs select (need-list).
+    // Phiếu PE Nháp + (tùy chọn) SelectedSupplierId pre-set. KHÔNG tự thêm participating
+    // row — caller quyết định để cô lập nhánh clear vs select.
     private static async Task<PurchaseEvaluation> SeedPeAsync(
         TestApplicationDbContext db, Guid? selectedSupplierId, string code = "PE-SW")
     {
@@ -72,9 +82,54 @@ public class PeSelectWinnerClearTests
         return pe;
     }
 
-    // Gắn supplier vào participating-list (PurchaseEvaluationSuppliers) của phiếu.
-    // Return PES row Id để assert IsWinner.
-    private static async Task<Guid> AddParticipatingAsync(
+    // 1 hạng mục (Detail) cho phiếu. Winner chọn theo hạng mục → mọi command cần DetailId này.
+    private static async Task<Guid> SeedDetailAsync(
+        TestApplicationDbContext db, Guid peId, string groupCode = DetailGroupCode)
+    {
+        var detail = new PurchaseEvaluationDetail
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationId = peId,
+            GroupCode = groupCode,
+            GroupName = "Bê tông",
+            NoiDung = "Concrete M100",
+            Order = 0,
+        };
+        db.PurchaseEvaluationDetails.Add(detail);
+        await db.SaveChangesAsync(CancellationToken.None);
+        return detail.Id;
+    }
+
+    // Gắn supplier vào participating-list + 1 quote thuộc detailId. isSelected pin pre-state
+    // (quote.IsSelected + pes.IsWinner giữ invariant). SelectWinner sẽ flip IsSelected của
+    // quote NÀY → derive IsWinner. Return PES row Id.
+    private static async Task<Guid> AddParticipatingWithQuoteAsync(
+        TestApplicationDbContext db, Guid peId, Guid supplierId, Guid detailId,
+        bool isSelected = false, decimal thanhTien = 100m, int order = 0)
+    {
+        var row = new PurchaseEvaluationSupplier
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationId = peId,
+            SupplierId = supplierId,
+            Order = order,
+            IsWinner = isSelected,   // derived == Any(quote.IsSelected)
+        };
+        db.PurchaseEvaluationSuppliers.Add(row);
+        db.PurchaseEvaluationQuotes.Add(new PurchaseEvaluationQuote
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationDetailId = detailId,
+            PurchaseEvaluationSupplierId = row.Id,
+            ThanhTien = thanhTien,
+            IsSelected = isSelected,
+        });
+        await db.SaveChangesAsync(CancellationToken.None);
+        return row.Id;
+    }
+
+    // Participating-row THUẦN (không quote) — cho test derive-invariant qua UpsertQuote.
+    private static async Task<Guid> AddParticipatingNoQuoteAsync(
         TestApplicationDbContext db, Guid peId, Guid supplierId, int order = 0)
     {
         var row = new PurchaseEvaluationSupplier
@@ -98,52 +153,48 @@ public class PeSelectWinnerClearTests
             .FirstAsync();
 
     // ============================================================
-    // 1. CLEAR branch ([] = bỏ chọn tất cả — trục quan trọng nhất)
+    // 1. CLEAR branch ([] = bỏ chọn cho hạng mục — trục quan trọng nhất)
     // ============================================================
 
     [Fact]
     public async Task Clear_PhieuHasSelectedWinner_SetsSelectedSupplierIdNull_AllRowsNotWinner()
     {
-        // ⭐ Phiếu đang có 1 winner (s1, IsWinner=true) + s1 trong participating-list →
-        // gọi SupplierIds=[] → clear: SelectedSupplierId=null + s1.IsWinner=false.
+        // ⭐ Phiếu đang có 1 winner (s1, quote IsSelected=true → IsWinner=true) + s1 trong
+        // participating-list → gọi SupplierIds=[] cho hạng mục → clear: quote IsSelected=false,
+        // IsWinner derive=false, SelectedSupplierId=null.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-A");
         var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
-        // Pre-set s1 = winner (mô phỏng phiếu đã chọn trước).
-        var row = await db.PurchaseEvaluationSuppliers.FirstAsync(s => s.SupplierId == s1.Id);
-        row.IsWinner = true;
-        await db.SaveChangesAsync(CancellationToken.None);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: Array.Empty<Guid>());
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>());
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
         reloaded.SelectedSupplierId.Should().BeNull("bỏ chọn = clear winner về none");
-        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("clear → mọi supplier-row IsWinner=false");
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("clear → quote IsSelected=false → IsWinner=false");
     }
 
     [Fact]
     public async Task Clear_EmptyList_AllRowsNotWinner_NoConflict()
     {
-        // Trục cốt lõi nhánh clear: SKIP validate participating-list (list rỗng = không
-        // có id cần kiểm). Phiếu có 2 NCC tham gia, s1 đang là winner → clear [] →
-        // KHÔNG ném + cả 2 row IsWinner=false + SelectedSupplierId=null.
+        // Trục cốt lõi nhánh clear: SKIP validate participating-list (list rỗng = không có id
+        // cần kiểm). Phiếu 2 NCC tham gia, s1 winner (quote sel=true) → clear [] cho hạng mục →
+        // KHÔNG ném + cả 2 IsWinner=false + SelectedSupplierId=null.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-1");
         var s2 = await SeedSupplierAsync(db, "NCC-2");
         var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
-        var r1 = await db.PurchaseEvaluationSuppliers.FirstAsync(s => s.SupplierId == s1.Id);
-        r1.IsWinner = true;
-        await db.SaveChangesAsync(CancellationToken.None);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: Array.Empty<Guid>());
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>());
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().NotThrowAsync("clear [] KHÔNG validate participating-list");
@@ -156,14 +207,16 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Clear_PhieuAlreadyNull_IsIdempotent_StaysNull_NoThrow()
     {
-        // Phiếu vốn-dĩ chưa chọn winner (SelectedSupplierId=null, không row IsWinner) →
-        // clear [] lần nữa = idempotent, vẫn null, không ném. Empty list cũng không cản.
+        // Phiếu vốn-dĩ chưa chọn winner (SelectedSupplierId=null, không quote IsSelected) →
+        // clear [] cho hạng mục lần nữa = idempotent, vẫn null, không ném. Cần seed detail
+        // (handler load Detail thuộc phiếu). Không có supplier/quote.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
+        var detailId = await SeedDetailAsync(db, pe.Id);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: Array.Empty<Guid>());
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>());
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().NotThrowAsync();
@@ -174,22 +227,23 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Clear_WritesChangelog_WithBoChonSummary()
     {
-        // Nhánh clear vẫn ghi 1 Changelog Header/Update với Summary "Bỏ chọn đơn vị
-        // NCC/TP trúng thầu" (phân biệt với "Chọn {n} đơn vị..." của nhánh select).
+        // Nhánh clear ghi 1 Changelog Header/Update Summary "Bỏ chọn NCC/TP trúng thầu cho
+        // hạng mục {GroupCode}" (phân biệt với "Chọn {n}..." của nhánh select).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-A");
         var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: Array.Empty<Guid>());
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>());
         await handler.Handle(cmd, CancellationToken.None);
 
         var log = await db.PurchaseEvaluationChangelogs.AsNoTracking()
             .Where(c => c.PurchaseEvaluationId == pe.Id)
             .SingleAsync();
-        log.Summary.Should().Be("Bỏ chọn đơn vị NCC/TP trúng thầu");
+        log.Summary.Should().Be($"Bỏ chọn NCC/TP trúng thầu cho hạng mục {DetailGroupCode}");
         log.EntityType.Should().Be(PurchaseEvaluationEntityType.Header);
         log.Action.Should().Be(ChangelogAction.Update);
     }
@@ -201,16 +255,17 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_OneSupplierInList_SetsSelectedSupplierId_RowIsWinner()
     {
-        // Happy-path single-winner: 1 supplier hợp lệ (thuộc participating-list) →
-        // SelectedSupplierId = đúng id (count==1 sync) + row IsWinner=true.
+        // Happy-path single-winner: 1 supplier hợp lệ (trong list, có quote cho hạng mục) →
+        // quote IsSelected=true → IsWinner=true + SelectedSupplierId = đúng id (count==1 sync).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-WIN");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id });
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -221,22 +276,20 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_ChangeWinner_FromS1ToS2_BothInList_UpdatesToS2_OnlyS2IsWinner()
     {
-        // Đổi winner: phiếu đang chọn s1 → chọn [s2] (cả 2 trong list) → SelectedSupplierId
-        // chuyển s2 + s2.IsWinner=true + s1.IsWinner=false (set false phần còn lại).
+        // Đổi winner: phiếu đang chọn s1 (quote sel=true) → chọn [s2] cho hạng mục → s2 quote
+        // IsSelected=true + s1 quote IsSelected=false → SelectedSupplierId=s2 + s2.IsWinner=true
+        // + s1.IsWinner=false.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-1");
         var s2 = await SeedSupplierAsync(db, "NCC-2");
         var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
-        // s1 đang là winner.
-        var r1 = await db.PurchaseEvaluationSuppliers.FirstAsync(s => s.SupplierId == s1.Id);
-        r1.IsWinner = true;
-        await db.SaveChangesAsync(CancellationToken.None);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s2.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s2.Id });
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -248,20 +301,18 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_SupplierNotInParticipatingList_ThrowsConflict_NoMutate()
     {
-        // Supplier không thuộc participating-list của phiếu → Conflict. IsWinner +
-        // SelectedSupplierId giữ nguyên (throw TRƯỚC khi set + SaveChanges).
+        // Supplier không thuộc participating-list → Conflict. IsWinner + SelectedSupplierId giữ
+        // nguyên (throw TRƯỚC khi flip IsSelected + SaveChanges).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
-        var s1 = await SeedSupplierAsync(db, "NCC-IN");      // trong list
+        var s1 = await SeedSupplierAsync(db, "NCC-IN");      // trong list (winner)
         var outsider = await SeedSupplierAsync(db, "NCC-OUT"); // không trong list
         var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
-        var r1 = await db.PurchaseEvaluationSuppliers.FirstAsync(s => s.SupplierId == s1.Id);
-        r1.IsWinner = true;
-        await db.SaveChangesAsync(CancellationToken.None);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { outsider.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { outsider.Id });
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().ThrowAsync<ConflictException>()
@@ -275,18 +326,18 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_OneIdInListOneOutside_ThrowsConflict_NoPartialMutate()
     {
-        // Multi-select với 1 id ngoài list (s1 trong, outsider ngoài) → Conflict (mỗi id
-        // phải thuộc list). KHÔNG partial-write: s1.IsWinner KHÔNG bị set true dù hợp lệ
-        // (validate TRƯỚC khi set IsWinner cho toàn bộ rows).
+        // Multi-select với 1 id ngoài list (s1 trong, outsider ngoài) → Conflict. KHÔNG
+        // partial-write: s1.IsWinner KHÔNG bị set true dù hợp lệ (validate TRƯỚC khi flip IsSelected).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-OK");
         var outsider = await SeedSupplierAsync(db, "NCC-FORGE");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, outsider.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, outsider.Id });
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().ThrowAsync<ConflictException>()
@@ -295,25 +346,26 @@ public class PeSelectWinnerClearTests
     }
 
     // ============================================================
-    // 3. SELECT branch — MULTI winner (≥2 → joint winner, SelectedSupplierId=null)
-    //    [TASK 2.1] regression cho hành vi multi-winner mới (Mig 58).
+    // 3. SELECT branch — MULTI winner CÙNG HẠNG MỤC (≥2 → joint, SelectedSupplierId=null)
+    //    [multi-NCC] ≥2 NCC/TP trúng CÙNG 1 hạng mục.
     // ============================================================
 
     [Fact]
     public async Task Select_TwoSuppliers_BothIsWinner_SelectedSupplierIdNull()
     {
-        // Chọn 2 đơn vị cùng trúng → cả 2 IsWinner=true, SelectedSupplierId=null (≥2 →
-        // không còn "1 winner" duy nhất). Trục multi-winner cốt lõi.
+        // Chọn 2 đơn vị cùng trúng 1 hạng mục → cả 2 quote IsSelected=true → cả 2 IsWinner=true,
+        // SelectedSupplierId=null (≥2 → không "1 winner" duy nhất). Trục multi-NCC cốt lõi.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-J1");
         var s2 = await SeedSupplierAsync(db, "NCC-J2");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, s2.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, s2.Id });
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -325,8 +377,8 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_ThreeOfFour_ThreeIsWinner_NonSelectedIsFalse_SelectedSupplierIdNull()
     {
-        // 4 NCC tham gia, chọn 3 → đúng 3 row IsWinner=true, NCC thứ 4 IsWinner=false,
-        // SelectedSupplierId=null. Verify "set false phần còn lại" với nhiều row.
+        // 4 NCC chào cùng hạng mục, chọn 3 → đúng 3 quote IsSelected=true (3 IsWinner), NCC thứ 4
+        // quote IsSelected=false (IsWinner=false), SelectedSupplierId=null.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-Q1");
@@ -334,13 +386,14 @@ public class PeSelectWinnerClearTests
         var s3 = await SeedSupplierAsync(db, "NCC-Q3");
         var s4 = await SeedSupplierAsync(db, "NCC-Q4");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
-        await AddParticipatingAsync(db, pe.Id, s3.Id, order: 2);
-        await AddParticipatingAsync(db, pe.Id, s4.Id, order: 3);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s3.Id, detailId, isSelected: false, order: 2);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s4.Id, detailId, isSelected: false, order: 3);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, s2.Id, s3.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, s2.Id, s3.Id });
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -354,16 +407,17 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_DuplicateIds_Deduped_TreatedAsSingleWinner_SelectedSupplierIdSet()
     {
-        // FE gửi trùng id [s1, s1] → Distinct → count==1 → đối xử single-winner:
-        // s1.IsWinner=true + SelectedSupplierId=s1 (KHÔNG bị coi là ≥2 do trùng).
+        // FE gửi trùng id [s1, s1] → Distinct → count==1 → single-winner: s1.IsWinner=true +
+        // SelectedSupplierId=s1 (KHÔNG bị coi là ≥2 do trùng).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-DUP");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false);
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, s1.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, s1.Id });
         await handler.Handle(cmd, CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -374,25 +428,25 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_MultiThenClear_RoundTrip_AllWinnersReset()
     {
-        // Round-trip: chọn 2 (joint) → rồi clear [] → cả 2 IsWinner về false +
-        // SelectedSupplierId=null. Chứng minh clear reset đúng kể cả từ trạng thái multi.
+        // Round-trip: chọn 2 (joint) → rồi clear [] → cả 2 IsWinner về false + SelectedSupplierId=null.
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-R1");
         var s2 = await SeedSupplierAsync(db, "NCC-R2");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
         var handler = BuildHandler(db);
 
         await handler.Handle(
-            new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, s2.Id }),
+            new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, s2.Id }),
             CancellationToken.None);
         (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("sau chọn 2");
         (await IsWinnerAsync(db, pe.Id, s2.Id)).Should().BeTrue();
 
         await handler.Handle(
-            new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: Array.Empty<Guid>()),
+            new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>()),
             CancellationToken.None);
 
         var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
@@ -404,43 +458,42 @@ public class PeSelectWinnerClearTests
     [Fact]
     public async Task Select_MultiWinner_WritesChangelog_WithChonNSummary()
     {
-        // Multi-winner ghi Changelog Summary "Chọn {n} đơn vị NCC/TP trúng thầu" (n = số
-        // đơn vị chọn). Verify count chính xác trong message.
+        // Multi-winner ghi Changelog Summary "Chọn {n} NCC/TP trúng thầu cho hạng mục {GroupCode}".
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var s1 = await SeedSupplierAsync(db, "NCC-CL1");
         var s2 = await SeedSupplierAsync(db, "NCC-CL2");
         var pe = await SeedPeAsync(db, selectedSupplierId: null);
-        await AddParticipatingAsync(db, pe.Id, s1.Id, order: 0);
-        await AddParticipatingAsync(db, pe.Id, s2.Id, order: 1);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false, order: 0);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s2.Id, detailId, isSelected: false, order: 1);
         var handler = BuildHandler(db);
 
         await handler.Handle(
-            new SelectPurchaseEvaluationWinnerCommand(pe.Id, SupplierIds: new[] { s1.Id, s2.Id }),
+            new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s1.Id, s2.Id }),
             CancellationToken.None);
 
         var log = await db.PurchaseEvaluationChangelogs.AsNoTracking()
             .Where(c => c.PurchaseEvaluationId == pe.Id)
             .SingleAsync();
-        log.Summary.Should().Be("Chọn 2 đơn vị NCC/TP trúng thầu");
+        log.Summary.Should().Be($"Chọn 2 NCC/TP trúng thầu cho hạng mục {DetailGroupCode}");
         log.EntityType.Should().Be(PurchaseEvaluationEntityType.Header);
         log.Action.Should().Be(ChangelogAction.Update);
     }
 
     // ============================================================
-    // 4. PE existence — chung mọi nhánh (check TRƯỚC khi rẽ nhánh SupplierIds)
+    // 4. Existence guards — PE + Detail (check TRƯỚC khi rẽ nhánh SupplierIds)
     // ============================================================
 
     [Fact]
     public async Task UnknownPe_Clear_ThrowsNotFound_BeforeBranch()
     {
-        // PE không tồn tại → NotFound("PurchaseEvaluation") ngay đầu handler, TRƯỚC
-        // khi xét SupplierIds (kể cả nhánh clear [] cũng không bỏ qua existence).
+        // PE không tồn tại → NotFound("PurchaseEvaluation") ngay đầu handler (TRƯỚC Detail + SupplierIds).
         using var fix = new SqliteDbFixture();
         var db = fix.Db;
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(Guid.NewGuid(), SupplierIds: Array.Empty<Guid>());
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(Guid.NewGuid(), Guid.NewGuid(), SupplierIds: Array.Empty<Guid>());
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().ThrowAsync<NotFoundException>();
@@ -454,9 +507,190 @@ public class PeSelectWinnerClearTests
         var s1 = await SeedSupplierAsync(db, "NCC-A");
         var handler = BuildHandler(db);
 
-        var cmd = new SelectPurchaseEvaluationWinnerCommand(Guid.NewGuid(), SupplierIds: new[] { s1.Id });
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(Guid.NewGuid(), Guid.NewGuid(), SupplierIds: new[] { s1.Id });
         var act = async () => await handler.Handle(cmd, CancellationToken.None);
 
         await act.Should().ThrowAsync<NotFoundException>();
     }
+
+    [Fact]
+    public async Task UnknownDetail_NotBelongingToPhieu_ThrowsNotFound()
+    {
+        // [multi-NCC] Detail phải thuộc phiếu — DetailId lạ (random Guid) → NotFound("PurchaseEvaluationDetail").
+        // Chặn cross-phiếu / stale detail. Kiểm SAU PE-existence, TRƯỚC supplier validate.
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-A");
+        var pe = await SeedPeAsync(db, selectedSupplierId: null);
+        var validDetailId = await SeedDetailAsync(db, pe.Id);   // phiếu CÓ 1 detail hợp lệ
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, validDetailId);
+        var handler = BuildHandler(db);
+
+        // cmd truyền DetailId LẠ (không thuộc phiếu) → NotFound TRƯỚC supplier validate.
+        var cmd = new SelectPurchaseEvaluationWinnerCommand(pe.Id, Guid.NewGuid(), SupplierIds: new[] { s1.Id });
+        var act = async () => await handler.Handle(cmd, CancellationToken.None);
+
+        await act.Should().ThrowAsync<NotFoundException>()
+            .WithMessage("*PurchaseEvaluationDetail*");
+    }
+
+    // ============================================================
+    // 5. [multi-NCC NEW test (d)] DERIVE INVARIANT: Supplier.IsWinner == Any(Quote.IsSelected)
+    //    duy trì qua UpsertQuote + SelectWinner + seed. Nguồn-sự-thật = Quote.IsSelected.
+    // ============================================================
+
+    [Fact]
+    public async Task DeriveInvariant_IsWinnerEqualsAnySelectedQuote_AfterUpsertQuoteAndSelectWinner()
+    {
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-INV1");
+        var s2 = await SeedSupplierAsync(db, "NCC-INV2");
+        var pe = await SeedPeAsync(db, selectedSupplierId: null);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        var s1Row = await AddParticipatingNoQuoteAsync(db, pe.Id, s1.Id, order: 0);
+        var s2Row = await AddParticipatingNoQuoteAsync(db, pe.Id, s2.Id, order: 1);
+
+        var upsert = BuildUpsertQuoteHandler(db);
+        var select = BuildHandler(db);
+
+        // Step 1 — UpsertQuote (Detail × s1) IsSelected=true → handler set s1.IsWinner=true.
+        await upsert.Handle(new UpsertPurchaseEvaluationQuoteCommand(
+            pe.Id, detailId, s1Row, BgVat: 0m, ChuaVat: 0m, ThanhTien: 100m, IsSelected: true, Note: null),
+            CancellationToken.None);
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("UpsertQuote IsSelected=true → derive IsWinner=true");
+
+        // Step 2 — UpsertQuote (Detail × s2) IsSelected=false → s2.IsWinner=false.
+        await upsert.Handle(new UpsertPurchaseEvaluationQuoteCommand(
+            pe.Id, detailId, s2Row, BgVat: 0m, ChuaVat: 0m, ThanhTien: 200m, IsSelected: false, Note: null),
+            CancellationToken.None);
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s2.Id)).Should().BeFalse("UpsertQuote IsSelected=false → IsWinner=false");
+
+        // Step 3 — SelectWinner [s2] cho hạng mục → s2 quote IsSelected=true, s1 quote IsSelected=false.
+        await select.Handle(
+            new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: new[] { s2.Id }),
+            CancellationToken.None);
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("SelectWinner đổi sang s2 → s1 quote IsSelected=false → IsWinner=false");
+        (await IsWinnerAsync(db, pe.Id, s2.Id)).Should().BeTrue("s2 quote IsSelected=true → IsWinner=true");
+
+        // Step 4 — SelectWinner [] clear → cả 2 quote IsSelected=false → cả 2 IsWinner=false.
+        await select.Handle(
+            new SelectPurchaseEvaluationWinnerCommand(pe.Id, detailId, SupplierIds: Array.Empty<Guid>()),
+            CancellationToken.None);
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse();
+        (await IsWinnerAsync(db, pe.Id, s2.Id)).Should().BeFalse();
+    }
+
+    // ============================================================
+    // [S114 Bước 4 verify — MUST/SHOULD] Delete-path re-derive IsWinner (writer bị sót ở implement)
+    // ============================================================
+
+    [Fact]
+    public async Task DeleteQuote_LastSelectedQuoteOfSupplier_ClearsIsWinner_NoPhantom()
+    {
+        // ⭐ BUG (Bước 4): DeleteQuoteHandler Remove(quote) KHÔNG re-derive IsWinner → xóa quote
+        // IsSelected CUỐI của 1 NCC để IsWinner kẹt=true trong khi Any(IsSelected)=false → phantom
+        // winner → CreateContract sinh HĐ giaTri=0. Test-before: assert IsWinner về false + invariant.
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-DQ");
+        var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        var rowId = await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true);
+        var quoteId = await db.PurchaseEvaluationQuotes.AsNoTracking()
+            .Where(q => q.PurchaseEvaluationSupplierId == rowId).Select(q => q.Id).FirstAsync();
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("pre-state: quote IsSelected=true → IsWinner=true");
+
+        var del = new DeletePurchaseEvaluationQuoteCommandHandler(db, new FakeCurrentUser());
+        await del.Handle(new DeletePurchaseEvaluationQuoteCommand(pe.Id, quoteId), CancellationToken.None);
+
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("xóa quote-selected cuối → IsWinner về false");
+        var reloaded = await db.PurchaseEvaluations.AsNoTracking().FirstAsync(x => x.Id == pe.Id);
+        reloaded.SelectedSupplierId.Should().BeNull("0 winner → SelectedSupplierId=null");
+    }
+
+    [Fact]
+    public async Task DeleteDetail_WithSupplierLastSelectedQuote_ClearsIsWinner()
+    {
+        // ⭐ BUG (Bước 4): DeleteDetailHandler Remove(entity) cascade xóa quotes NHƯNG không re-derive
+        // IsWinner → NCC mất quote-selected cuối bị kẹt IsWinner=true. Test-before.
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-DD");
+        var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: true);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("pre-state IsWinner=true");
+
+        var del = new DeletePurchaseEvaluationDetailCommandHandler(db, new FakeCurrentUser());
+        await del.Handle(new DeletePurchaseEvaluationDetailCommand(pe.Id, detailId), CancellationToken.None);
+
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("xóa hạng mục chứa quote-selected cuối → IsWinner=false");
+    }
+
+    [Fact]
+    public async Task DeleteDetail_SupplierStillWinsAnotherDetail_KeepsIsWinner()
+    {
+        // Guard: re-derive per-PHIẾU (không over-clear). Xóa 1 hạng mục nhưng NCC còn thắng hạng
+        // mục KHÁC → IsWinner GIỮ true.
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-2D");
+        var pe = await SeedPeAsync(db, selectedSupplierId: s1.Id);
+        var detailA = await SeedDetailAsync(db, pe.Id, "A.I");
+        var detailB = await SeedDetailAsync(db, pe.Id, "B.I");
+        var rowId = await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailA, isSelected: true);
+        var up = BuildUpsertQuoteHandler(db);
+        await up.Handle(new UpsertPurchaseEvaluationQuoteCommand(pe.Id, detailB, rowId, 0, 0, 50m, true, null), CancellationToken.None);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue();
+
+        var del = new DeletePurchaseEvaluationDetailCommandHandler(db, new FakeCurrentUser());
+        await del.Handle(new DeletePurchaseEvaluationDetailCommand(pe.Id, detailA), CancellationToken.None);
+
+        await AssertWinnerInvariantAsync(db, pe.Id);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("vẫn thắng detailB → IsWinner giữ true");
+    }
+
+    [Fact]
+    public async Task UpsertQuote_UpdateBranch_TogglesIsWinnerCorrectly()
+    {
+        // [Bước 4 SHOULD] Coverage-gap: UPDATE-path (quote đã tồn tại) re-derive dùng loại-trừ
+        // q.Id != existing.Id (né stale-DB-read). Test-before đã có, giữ để cover UPDATE branch.
+        using var fix = new SqliteDbFixture();
+        var db = fix.Db;
+        var s1 = await SeedSupplierAsync(db, "NCC-UP");
+        var pe = await SeedPeAsync(db, selectedSupplierId: null);
+        var detailId = await SeedDetailAsync(db, pe.Id);
+        var rowId = await AddParticipatingWithQuoteAsync(db, pe.Id, s1.Id, detailId, isSelected: false);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("quote tồn tại nhưng chưa selected");
+        var up = BuildUpsertQuoteHandler(db);
+
+        await up.Handle(new UpsertPurchaseEvaluationQuoteCommand(pe.Id, detailId, rowId, 0, 0, 100m, true, null), CancellationToken.None);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeTrue("UPDATE IsSelected=true → IsWinner=true");
+        await AssertWinnerInvariantAsync(db, pe.Id);
+
+        await up.Handle(new UpsertPurchaseEvaluationQuoteCommand(pe.Id, detailId, rowId, 0, 0, 100m, false, null), CancellationToken.None);
+        (await IsWinnerAsync(db, pe.Id, s1.Id)).Should().BeFalse("UPDATE IsSelected=false (loại chính nó) → IsWinner=false");
+        await AssertWinnerInvariantAsync(db, pe.Id);
+    }
+
+    // Invariant checker: MỌI supplier-row → IsWinner == (tồn tại ÍT NHẤT 1 quote IsSelected của row).
+    private static async Task AssertWinnerInvariantAsync(TestApplicationDbContext db, Guid peId)
+    {
+        var rows = await db.PurchaseEvaluationSuppliers.AsNoTracking()
+            .Where(s => s.PurchaseEvaluationId == peId).ToListAsync();
+        foreach (var r in rows)
+        {
+            var anySelected = await db.PurchaseEvaluationQuotes.AsNoTracking()
+                .AnyAsync(q => q.PurchaseEvaluationSupplierId == r.Id && q.IsSelected);
+            r.IsWinner.Should().Be(anySelected,
+                $"invariant Supplier.IsWinner == Any(Quote.IsSelected) cho row SupplierId={r.SupplierId}");
+        }
+    }
 }

tests/SolutionErp.Infrastructure.Tests/Application/PeWorkItemBudgetTests.cs

@@ -593,10 +593,11 @@ public class PeWorkItemBudgetTests
     // =====================================================================
 
     // Seed 1 NCC thắng + 1 detail + 1 quote ThanhTien cho phiếu (winner tổng thể).
-    // [Mig 58 multi-winner] Tiêu chí "đã chọn thầu" nay = IsWinner trên supplier-row
-    // (KHÔNG còn SelectedSupplierId). Helper này set CẢ HAI để mô phỏng single-winner đúng
-    // nghiệp vụ (đúng 1 winner ⇒ SelectedSupplierId = winner đó được sync). Code GetDetail
-    // chỉ đọc IsWinner cho prevSelected*; SelectedSupplierId giữ để các path khác (banner FE).
+    // [multi-NCC 2026-07-12 cardinality-change] budgetSummary PreviousSelectedTotal +
+    // CurrentProposalTotal NAY = SUM ThanhTien quote ĐƯỢC CHỌN (Quote.IsSelected —
+    // PurchaseEvaluationFeatures.cs:911-926 `where q.IsSelected`), KHÔNG còn build từ IsWinner.
+    // PreviousSelectedCount vẫn dùng IsWinner (existence). Helper set CẢ quote.IsSelected=true +
+    // pes.IsWinner=true (invariant) → tổng tiền lọt đúng + count đúng. SelectedSupplierId sync caller.
     private static async Task SeedWinnerWithQuoteAsync(
         TestApplicationDbContext db, PurchaseEvaluation pe, Guid supplierId, decimal thanhTien)
     {
@@ -606,7 +607,7 @@ public class PeWorkItemBudgetTests
             PurchaseEvaluationId = pe.Id,
             SupplierId = supplierId,
             Order = 0,
-            IsWinner = true,   // [Mig 58] nguồn-sự-thật mới cho "đơn vị trúng"
+            IsWinner = true,   // existence (PreviousSelectedCount) — derived == Any(IsSelected)
         };
         var detail = new PurchaseEvaluationDetail
         {
@@ -625,6 +626,7 @@ public class PeWorkItemBudgetTests
             PurchaseEvaluationDetailId = detail.Id,
             PurchaseEvaluationSupplierId = pes.Id,
             ThanhTien = thanhTien,
+            IsSelected = true,   // [multi-NCC] báo giá được chọn → vào PrevSelectedTotal/CurrentProposalTotal
         });
         await db.SaveChangesAsync(CancellationToken.None);
     }
@@ -665,6 +667,7 @@ public class PeWorkItemBudgetTests
                 PurchaseEvaluationDetailId = detail.Id,
                 PurchaseEvaluationSupplierId = pes.Id,
                 ThanhTien = thanhTien,
+                IsSelected = true,   // [multi-NCC] mỗi winner có báo giá được chọn → vào SUM IsSelected
             });
         }
         // pe.SelectedSupplierId GIỮ null (đã null từ SeedPeAsync) — đặc trưng ≥2 winner.

tests/SolutionErp.Infrastructure.Tests/Services/PeCcmThresholdFinalizeTests.cs

@@ -80,6 +80,11 @@ public class PeCcmThresholdFinalizeTests
 
     // Seed 1 NCC tham gia (winner) + 1 detail + 1 quote ThanhTien=amount → winner
     // quote sum = amount. Return supplierId (master ref) để pin SelectedSupplierId.
+    // [multi-NCC 2026-07-12 cardinality-change] ccm-delegate winnerQuoteTotal NAY = SUM
+    // ThanhTien quote ĐƯỢC CHỌN (Quote.IsSelected — service :884-889 `where q.IsSelected`),
+    // KHÔNG còn theo IsWinner supplier-row. Quote PHẢI IsSelected=true thì mới vào tổng
+    // → boundary test (b)/(b2) (gói >= ngưỡng → Conflict) mới đúng; nếu IsSelected=false thì
+    // tổng=0 luôn < ngưỡng → mất case Conflict. Set CẢ IsSelected + IsWinner (giữ invariant).
     private static async Task<Guid> SeedWinnerWithQuoteAsync(
         TestApplicationDbContext db, PurchaseEvaluation pe, decimal quoteThanhTien)
     {
@@ -89,7 +94,7 @@ public class PeCcmThresholdFinalizeTests
             PurchaseEvaluationId = pe.Id,
             SupplierId = supplierId,
             Order = 0,
-            IsWinner = true,   // [Mig 58] ccm-delegate winnerQuoteTotal đếm SUM theo IsWinner rows
+            IsWinner = true,   // derived == Any(quote.IsSelected)
         };
         var detail = new PurchaseEvaluationDetail
         {
@@ -106,6 +111,47 @@ public class PeCcmThresholdFinalizeTests
             PurchaseEvaluationDetailId = detail.Id,
             PurchaseEvaluationSupplierId = pes.Id,
             ThanhTien = quoteThanhTien,
+            IsSelected = true,   // [multi-NCC] báo giá được chọn → vào winnerQuoteTotal
+        });
+        await db.SaveChangesAsync(CancellationToken.None);
+        return supplierId;
+    }
+
+    // [multi-NCC 2026-07-12 — new test (c) threshold-crossing] Seed 1 winner-row với 2 quote:
+    // 1 ĐƯỢC CHỌN (selectedThanhTien) + 1 KHÔNG chọn (unselectedThanhTien). Tổng-theo-IsSelected
+    // = selectedThanhTien; tổng-theo-CŨ (whole-supplier IsWinner, gồm cả quote không chọn) =
+    // selected + unselected. Return supplierId.
+    private static async Task<Guid> SeedWinnerWithSelectedAndUnselectedQuoteAsync(
+        TestApplicationDbContext db, PurchaseEvaluation pe,
+        decimal selectedThanhTien, decimal unselectedThanhTien)
+    {
+        var supplierId = Guid.NewGuid();
+        var pes = new PurchaseEvaluationSupplier
+        {
+            PurchaseEvaluationId = pe.Id, SupplierId = supplierId, Order = 0, IsWinner = true,
+        };
+        var detailSel = new PurchaseEvaluationDetail
+        {
+            PurchaseEvaluationId = pe.Id, GroupCode = "A.I", GroupName = "Bê tông",
+            NoiDung = "Hạng mục ĐƯỢC chọn", Order = 0,
+        };
+        var detailUnsel = new PurchaseEvaluationDetail
+        {
+            PurchaseEvaluationId = pe.Id, GroupCode = "A.II", GroupName = "Thép",
+            NoiDung = "Hạng mục KHÔNG chọn", Order = 1,
+        };
+        db.PurchaseEvaluationSuppliers.Add(pes);
+        db.PurchaseEvaluationDetails.Add(detailSel);
+        db.PurchaseEvaluationDetails.Add(detailUnsel);
+        db.PurchaseEvaluationQuotes.Add(new PurchaseEvaluationQuote
+        {
+            PurchaseEvaluationDetailId = detailSel.Id, PurchaseEvaluationSupplierId = pes.Id,
+            ThanhTien = selectedThanhTien, IsSelected = true,
+        });
+        db.PurchaseEvaluationQuotes.Add(new PurchaseEvaluationQuote
+        {
+            PurchaseEvaluationDetailId = detailUnsel.Id, PurchaseEvaluationSupplierId = pes.Id,
+            ThanhTien = unselectedThanhTien, IsSelected = false,
         });
         await db.SaveChangesAsync(CancellationToken.None);
         return supplierId;
@@ -611,4 +657,50 @@ public class PeCcmThresholdFinalizeTests
                 .WithMessage("*giá chốt*");
         }
     }
+
+    // =====================================================================
+    // (c) [multi-NCC 2026-07-12 cardinality-change — NEW] THRESHOLD-CROSSING:
+    //     Winner có 1 quote ĐƯỢC CHỌN 500tr + 1 quote KHÔNG chọn 700tr.
+    //     • Tổng-theo-CŨ (whole-supplier IsWinner, gồm cả quote không chọn) = 1.2 tỷ ≥ ngưỡng
+    //       1 tỷ → nếu code còn dùng logic cũ = Conflict (SAI).
+    //     • Tổng-theo-MỚI (Quote.IsSelected only) = 500tr < 1 tỷ → CCM duyệt done miễn CEO
+    //       HỢP LỆ → finalize DaDuyet, KHÔNG throw.
+    //     Chống regression: chứng minh winnerQuoteTotal đọc IsSelected-subset, KHÔNG whole-supplier.
+    // =====================================================================
+    [Fact]
+    public async Task ApproveV2_CcmDelegation_WholeSupplierSumAboveButSelectedSubsetBelow_Finalizes_NoThrow()
+    {
+        var (svc, fix, db, _) = CreateService();
+        using (fix)
+        {
+            var ccm = (await fix.CreateUserAsync("ccmXc@fb.test", "CCM User", null, new[] { AppRoles.CostControl })).Id;
+            var ceo = (await fix.CreateUserAsync("ceoXc@fb.test", "CEO User", null, new[] { AppRoles.Director })).Id;
+
+            var wf = await SeedWorkflowAsync(db, new[]
+            {
+                new[] { ccm },   // Bước 1 = CCM (đứng đây)
+                new[] { ceo },   // Bước 2 = CEO (sẽ bị bỏ qua)
+            }, ceoThreshold: CeoThreshold);   // 1 tỷ
+
+            var pe = BuildPeAtApprovalSlot(wf.Id, selectedSupplierId: null, stepIdx: 0, levelOrder: 1, code: "PE-FB-XC");
+            db.PurchaseEvaluations.Add(pe);
+            await db.SaveChangesAsync(CancellationToken.None);
+            // Selected 500tr + Unselected 700tr → whole-supplier=1.2 tỷ ≥ ngưỡng, IsSelected=500tr < ngưỡng.
+            var supplierId = await SeedWinnerWithSelectedAndUnselectedQuoteAsync(
+                db, pe, selectedThanhTien: 500_000_000m, unselectedThanhTien: 700_000_000m);
+            pe.SelectedSupplierId = supplierId;
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            // finalize theo IsSelected-subset (500tr < 1 tỷ) → KHÔNG throw, DaDuyet.
+            var act = async () => await ApproveAsync(svc, pe, ccm, new[] { AppRoles.CostControl },
+                finalizeByCcmDelegation: true,
+                approvedPriceAmount: ValidApprovedPrice, approvedPriceSource: ValidApprovedSource);
+
+            await act.Should().NotThrowAsync(
+                "winnerQuoteTotal đọc SUM Quote.IsSelected (500tr < ngưỡng); logic cũ whole-supplier 1.2 tỷ đã bị thay");
+            pe.Phase.Should().Be(PurchaseEvaluationPhase.DaDuyet, "CCM duyệt done miễn CEO — gói ĐƯỢC CHỌN < ngưỡng");
+            pe.CurrentWorkflowStepIndex.Should().BeNull();
+            pe.ApprovedPriceAmount.Should().Be(ValidApprovedPrice);
+        }
+    }
 }

tests/SolutionErp.Infrastructure.Tests/Services/PeSubmitGuardAndBypassTests.cs

@@ -96,9 +96,13 @@ public class PeSubmitGuardAndBypassTests
 
     // Seed 1 NCC tham gia (PurchaseEvaluationSupplier) cho winner + 1 detail + 1
     // quote ThanhTien=amount để winner quote sum > 0. Return supplierId (master ref).
-    // [Mig 58] Winner = supplier-row IsWinner=true (nguồn-sự-thật mới — submit guard +
-    // ccm-delegate + read DTO SUM theo IsWinner, KHÔNG còn theo SelectedSupplierId). Set
-    // IsWinner=true + sync SelectedSupplierId trong caller để mirror handler select-winner.
+    // [multi-NCC 2026-07-12 cardinality-change] Submit guard NAY đọc SUM theo
+    // Quote.IsSelected (nguồn-sự-thật per Detail×Supplier — PurchaseEvaluationWorkflowService
+    // :196-201 `where q.IsSelected`), KHÔNG còn IsWinner/SelectedSupplierId. Winner quote PHẢI
+    // IsSelected=true thì mới lọt selectedThanhTien (nếu không → "chưa chọn Đơn vị NCC/TP" bắn
+    // sai). Set CẢ quote.IsSelected=true + pes.IsWinner=true (invariant IsWinner==Any(IsSelected))
+    // để mirror handler select-winner. Test (3) ThanhTien=0 vẫn đúng: IsSelected=true → lọt
+    // list nhưng Sum≤0 → "chưa có giá chào thầu".
     private static async Task<Guid> SeedWinnerWithQuoteAsync(
         TestApplicationDbContext db, PurchaseEvaluation pe, decimal quoteThanhTien)
     {
@@ -108,7 +112,7 @@ public class PeSubmitGuardAndBypassTests
             PurchaseEvaluationId = pe.Id,
             SupplierId = supplierId,
             Order = 0,
-            IsWinner = true,   // [Mig 58] đánh dấu winner — submit guard đếm IsWinner rows
+            IsWinner = true,   // derived == Any(quote.IsSelected) — giữ đúng invariant
         };
         var detail = new PurchaseEvaluationDetail
         {
@@ -125,6 +129,7 @@ public class PeSubmitGuardAndBypassTests
             PurchaseEvaluationDetailId = detail.Id,
             PurchaseEvaluationSupplierId = pes.Id,
             ThanhTien = quoteThanhTien,
+            IsSelected = true,   // [multi-NCC] báo giá ĐƯỢC CHỌN → lọt SUM submit-guard/DTO/threshold
         });
         await db.SaveChangesAsync(CancellationToken.None);
         return supplierId;