[CLAUDE] Contract: W7 KHKK GD4 "Hop dong cung" 1-moc — HardCopiesPage x2 + ?type filter + hasSealedCopy badge + 3 test PIN (suite 590/0)

- BE: ListContractsQuery +ContractType? type (filter server-side F-C1/F-05) + DTO HasSealedCopy derive Attachments.Any(purpose=SealedCopy=3) — append-cuoi default false, 0 policy moi, 0 migration, attachment endpoints 0-diff (O-A giu)
- FE x2 SHA-PAIR: trang /hard-copies (list phase=9 hardcode + badge + panel upload multipart purpose=3 + Y kien cap duyet readonly) + 7 leaf Hdc_* re-point ?type=1..7 (coming-soon 0/0, menu 142 giu)
- Tests: ContractHardCopyTests 3 PIN (phase-only + type-filter Total-server-side + badge derive purpose=3 no-IsDeleted) — probe vi-phan 5/5 phan biet ban hong; suite 587->590/0
- Review: PASS-co-dieu-kien (FLAG-1 untracked da gate; FLAG-2/3 comment da va, SHA-pair C7DCC20B giu; +31/-4 errata BE self-report)

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

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

@@ -20,8 +20,11 @@ public class ContractsController(IMediator mediator) : ControllerBase
         [FromQuery] ContractPhase? phase = null,
         [FromQuery] Guid? supplierId = null,
         [FromQuery] Guid? projectId = null,
+        // [W7 S161] Lọc theo loại HĐ cho 7 leaf bản-cứng `Hdc_*`: `?type={1..7}&phase=9`.
+        // Nullable ⇒ bỏ trống = giữ nguyên hành vi cũ (0 breaking cho caller hiện có).
+        [FromQuery] ContractType? type = null,
         CancellationToken ct = default)
-        => Ok(await mediator.Send(new ListContractsQuery(phase, supplierId, projectId) { Page = page, PageSize = pageSize, Search = search, SortDesc = sortDesc }, ct));
+        => Ok(await mediator.Send(new ListContractsQuery(phase, supplierId, projectId, type) { Page = page, PageSize = pageSize, Search = search, SortDesc = sortDesc }, ct));
 
     // [S159-đợt5] Màn "Đã xóa" HĐ (chỉ-xem) — mirror PE /deleted (S155). Read-only,
     // policy root Contracts.Read (chặt hơn [Authorize] trần của class — không phá gì).