feat(downloads): add column layout reset action

src/renderer/views/downloads/DownloadsTable.tsx

@@ -512,6 +512,7 @@ export interface DownloadsTableHeaderProps {
   actions: DownloadsTableActions;
   columnOrder: readonly string[];
   gridTemplate: string;
+  onResetColumnLayout?: () => void;
   sortColumn: DownloadSortColumn;
   sortDirection: "asc" | "desc";
   selectedCount: number;
@@ -533,7 +534,7 @@ function moveColumnWithPointerActions(column: string, direction: -1 | 1, element
   actions.onColumnPointerUp(column, pointerEvent(clientX));
 }
 
-export function DownloadsTableHeader({ actions, columnOrder, gridTemplate, sortColumn, sortDirection, selectedCount, visibleIds }: DownloadsTableHeaderProps): ReactElement {
+export function DownloadsTableHeader({ actions, columnOrder, gridTemplate, onResetColumnLayout, sortColumn, sortDirection, selectedCount, visibleIds }: DownloadsTableHeaderProps): ReactElement {
   const allSelected = visibleIds.length > 0 && selectedCount === visibleIds.length;
   const mixedSelection = selectedCount > 0 && selectedCount < visibleIds.length;
   return (
@@ -574,7 +575,7 @@ export function DownloadsTableHeader({ actions, columnOrder, gridTemplate, sortC
           </div>
         );
       })}
-      <span className="downloads-action-cell" role="columnheader">Aktion</span>
+      <span className="downloads-action-cell downloads-header-action-cell" role="columnheader"><span>Aktion</span>{onResetColumnLayout ? <button aria-label="Spaltenlayout zurücksetzen" className="downloads-column-reset-button" onClick={onResetColumnLayout} title="Spaltenlayout zurücksetzen" type="button">↺</button> : null}</span>
     </div>
   );
 }

src/renderer/views/downloads/DownloadsView.tsx

@@ -53,6 +53,7 @@ export interface DownloadsViewModel extends DownloadsViewModelCore {
 }
 
 export interface DownloadsViewActions extends DownloadsTableActions {
+  onResetColumnLayout: () => void;
   onDisplayModeChange: (mode: DownloadDisplayMode) => void;
   onFilterChange: (filter: DownloadSidebarFilter) => void;
   onProviderFilterChange: (provider: string) => void;
@@ -148,7 +149,7 @@ export function DownloadsContent({ actions, model }: { actions: DownloadsViewAct
   return (
     <main className="downloads-content">
       <div className="downloads-table" role="table" aria-label="Downloads">
-        <DownloadsTableHeader actions={actions} columnOrder={model.columnOrder} gridTemplate={model.gridTemplate} selectedCount={model.actionableSelectedIds.length} sortColumn={model.sortColumn ?? "name"} sortDirection={model.sortDirection ?? "asc"} visibleIds={model.visibleRowIds} />
+        <DownloadsTableHeader actions={actions} columnOrder={model.columnOrder} gridTemplate={model.gridTemplate} onResetColumnLayout={actions.onResetColumnLayout} selectedCount={model.actionableSelectedIds.length} sortColumn={model.sortColumn ?? "name"} sortDirection={model.sortDirection ?? "asc"} visibleIds={model.visibleRowIds} />
         <VirtualizedDownloadsBody actions={actions} model={model} state={state} />
       </div>
     </main>

src/renderer/views/downloads/downloads.css

@@ -527,6 +527,21 @@
   padding: 0;
 }
 
+.downloads-header-action-cell {
+  flex-direction: column;
+  gap: 1px;
+  line-height: 11px;
+}
+
+.downloads-header-action-cell .downloads-column-reset-button {
+  width: 20px;
+  height: 20px;
+  min-height: 20px;
+  border-radius: 4px;
+  font-size: 15px;
+  line-height: 1;
+}
+
 .downloads-collapse-button {
   box-sizing: border-box;
   flex: 0 0 30px;

tests/downloads-view.test.tsx

@@ -95,6 +95,30 @@ describe("Downloadtabellen-Spalten", () => {
     expect(header.props.style.gridTemplateColumns).toBe(expected);
   });
 
+  it("exposes a header action that delegates resetting the column layout", () => {
+    const reset = vi.fn();
+    const actions = createActions({ onResetColumnLayout: reset });
+    const model = withRuntime(createInput());
+    const content = renderToStaticMarkup(<DownloadsContent actions={actions} model={model} />);
+    const header = DownloadsTableHeader({
+      actions,
+      columnOrder: model.columnOrder,
+      gridTemplate: model.gridTemplate,
+      onResetColumnLayout: actions.onResetColumnLayout,
+      selectedCount: 0,
+      sortColumn: "name",
+      sortDirection: "asc",
+      visibleIds: model.visibleRowIds
+    });
+    const button = findElement(header, (element) => element.type === "button" && element.props["aria-label"] === "Spaltenlayout zurücksetzen");
+
+    button.props.onClick();
+
+    expect(content).toContain('aria-label="Spaltenlayout zurücksetzen"');
+    expect(button.props.title).toBe("Spaltenlayout zurücksetzen");
+    expect(reset).toHaveBeenCalledTimes(1);
+  });
+
   it("never interpolates download grid tracks while column contents move", () => {
     const css = fs.readFileSync(path.join(process.cwd(), "src/renderer/views/downloads/downloads.css"), "utf8");
 
@@ -651,6 +675,7 @@ function createLargeInput(packageCount: number, itemCount: number, overrides: Pa
 
 function createActions(overrides: Partial<DownloadsViewActions> = {}): DownloadsViewActions {
   return {
+    onResetColumnLayout: () => {},
     onDisplayModeChange: () => {},
     onFilterChange: () => {},
     onProviderFilterChange: () => {},