Preserve QExcell active sheet in XLSX

src/io/excellOffice.test.ts

@@ -12,6 +12,7 @@ import {
   importXlsxFile,
   chartDataPoints,
   chartXmlToSheetChart,
+  workbookActiveSheetId,
   workbookRelationshipTargets,
   workbookSheetRefs,
   worksheetXmlToCells,
@@ -519,6 +520,39 @@ describe("excellOffice OOXML helpers", () => {
         }
       })
     ).toEqual({ rId3: "worksheets/sheet7.xml" });
+
+    expect(
+      workbookActiveSheetId(
+        {
+          workbook: {
+            bookViews: { workbookView: { activeTab: "1" } }
+          }
+        },
+        [
+          { id: "sheet-1" },
+          { id: "sheet-7" }
+        ]
+      )
+    ).toBe("sheet-7");
+  });
+
+  it("сохраняет и импортирует активный лист XLSX через workbookView activeTab", async () => {
+    const blob = await exportXlsxBlob({
+      id: "book-1",
+      title: "Активный лист.xlsx",
+      updatedAt: "2026-06-01T00:00:00.000Z",
+      activeSheet: "sheet-2",
+      sheets: [
+        { id: "sheet-1", name: "Первый", cells: { A1: "Первый" } },
+        { id: "sheet-2", name: "Второй", cells: { A1: "Второй" } }
+      ]
+    });
+    const zip = await JSZip.loadAsync(await blob.arrayBuffer());
+    const workbookXml = await zip.file("xl/workbook.xml")?.async("string");
+    const imported = await importXlsxFile(new File([blob], "Активный лист.xlsx", { type: blob.type }));
+
+    expect(workbookXml).toContain('<workbookView activeTab="1"/>');
+    expect(imported.activeSheet).toBe("sheet-2");
   });
 
   it("создает OOXML chart part для диаграммы XLSX", () => {