Normalize QExcell sheet names for XLSX export

src/io/excellOffice.test.ts

@@ -37,6 +37,7 @@ import {
   worksheetXmlToZoomScale,
   xlsxStylesXmlToCellFormatTable,
   xlsxThemeXmlToColors,
+  xlsxSafeSheetNames,
   xlsxCellToText
 } from "./excellOffice";
 
@@ -633,6 +634,38 @@ describe("excellOffice OOXML helpers", () => {
     expect(imported.activeSheet).toBe("sheet-2");
   });
 
+  it("normalizes XLSX sheet names to Excel-safe unique names on export", async () => {
+    expect(
+      xlsxSafeSheetNames([
+        { name: "Sales/2026:Q1*?" },
+        { name: "'Very long worksheet name that exceeds thirty one characters'" },
+        { name: "Sales 2026 Q1" },
+        { name: "'[]:*?/\\'" },
+        { name: "History" }
+      ])
+    ).toEqual(["Sales 2026 Q1", "Very long worksheet name that e", "Sales 2026 Q1 (2)", "Лист 4", "History 1"]);
+
+    const blob = await exportXlsxBlob({
+      id: "book-1",
+      title: "Safe sheet names.xlsx",
+      updatedAt: "2026-06-01T00:00:00.000Z",
+      activeSheet: "sheet-1",
+      sheets: [
+        { id: "sheet-1", name: "Sales/2026:Q1*?", printArea: "A1:B2", cells: { A1: "Sales" } },
+        { id: "sheet-2", name: "Sales 2026 Q1", cells: { A1: "Duplicate" } }
+      ]
+    });
+    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], "Safe sheet names.xlsx", { type: blob.type }));
+
+    expect(workbookXml).toContain('<sheet name="Sales 2026 Q1" sheetId="1" r:id="rId1"/>');
+    expect(workbookXml).toContain('<sheet name="Sales 2026 Q1 (2)" sheetId="2" r:id="rId2"/>');
+    expect(workbookXml).toContain('<definedName name="_xlnm.Print_Area" localSheetId="0">\'Sales 2026 Q1\'!$A$1:$B$2</definedName>');
+    expect(imported.sheets.map((sheet) => sheet.name)).toEqual(["Sales 2026 Q1", "Sales 2026 Q1 (2)"]);
+    expect(imported.sheets[0].printArea).toBe("A1:B2");
+  });
+
   it("сохраняет и импортирует область печати XLSX через definedName _xlnm.Print_Area", async () => {
     expect(
       workbookPrintAreas(