Preserve QExcell strikethrough formatting

src/features/qexcell/QExcell.tsx

@@ -19,6 +19,7 @@ import {
   Plus,
   Save,
   Sigma,
+  Strikethrough,
   Trash2,
   Type,
   Underline
@@ -114,6 +115,7 @@ function normalizedCellFormat(format: CellFormat): CellFormat | undefined {
     ...(format.bold ? { bold: true } : {}),
     ...(format.italics ? { italics: true } : {}),
     ...(format.underline ? { underline: true } : {}),
+    ...(format.strike ? { strike: true } : {}),
     ...(fontSize ? { fontSize } : {}),
     ...(textColor ? { textColor } : {}),
     ...(fillColor ? { fillColor } : {}),
@@ -125,10 +127,11 @@ function normalizedCellFormat(format: CellFormat): CellFormat | undefined {
 }
 
 function cellInputStyle(format?: CellFormat): CSSProperties {
+  const textDecoration = [format?.underline ? "underline" : "", format?.strike ? "line-through" : ""].filter(Boolean).join(" ");
   return {
     ...(format?.bold ? { fontWeight: 700 } : {}),
     ...(format?.italics ? { fontStyle: "italic" } : {}),
-    ...(format?.underline ? { textDecoration: "underline" } : {}),
+    ...(textDecoration ? { textDecoration } : {}),
     ...(format?.fontSize ? { fontSize: `${format.fontSize}pt` } : {}),
     ...(format?.textColor ? { color: `#${format.textColor}` } : {}),
     ...(format?.fillColor ? { backgroundColor: `#${format.fillColor}` } : {}),
@@ -249,7 +252,7 @@ export function QExcell({ workbook, onChange }: QExcellProps) {
     });
   }
 
-  function toggleSelectedFormat(key: "bold" | "italics" | "underline") {
+  function toggleSelectedFormat(key: "bold" | "italics" | "underline" | "strike") {
     updateCellFormat(selectedCell, { [key]: !selectedCellFormat[key] });
   }
 
@@ -490,6 +493,15 @@ export function QExcell({ workbook, onChange }: QExcellProps) {
             >
               <Underline size={16} />
             </button>
+            <button
+              className={`icon-button format-toggle ${selectedCellFormat.strike ? "is-active" : ""}`.trim()}
+              type="button"
+              onClick={() => toggleSelectedFormat("strike")}
+              title="Зачеркнуть"
+              aria-label="Зачеркнуть"
+            >
+              <Strikethrough size={16} />
+            </button>
             {horizontalAlignOptions.map((option) => {
               const Icon = option.icon;
               const isActive = selectedCellFormat.horizontalAlign === option.value;