feat(downloads): restore sorting and stable availability

Make Service sortable by visible provider labels, keep pointer sorting distinct from column dragging, preserve keyboard sorting, infer active and completed transfers as online, and retain definitive availability across item and package resets. Keep manual extraction and package-status changes out of this selective rebuild.

src/renderer/App.tsx

@@ -1404,7 +1404,7 @@ function sortPackageOrderByHoster(order: string[], packages: Record<string, Pack
   return sorted;
 }
 
-function sortPackageOrderByProgress(order: string[], packages: Record<string, PackageEntry>, items: Record<string, DownloadItem>, descending: boolean): string[] {
+function sortPackageOrderByProgress(order: string[], packages: Record<string, PackageEntry>, items: Record<string, DownloadItem>, descending: boolean): string[] {
   const sorted = [...order];
   sorted.sort((a, b) => {
     const progressA = computePackageProgress(packages[a], items);
@@ -1412,8 +1412,27 @@ function sortPackageOrderByProgress(order: string[], packages: Record<string, Pa
     const cmp = progressA - progressB;
     return descending ? -cmp : cmp;
   });
-  return sorted;
-}
+  return sorted;
+}
+
+export function sortPackageOrderByService(
+  order: string[],
+  packages: Record<string, PackageEntry>,
+  items: Record<string, DownloadItem>,
+  descending: boolean,
+  visibleItemsByPackage: Record<string, readonly DownloadItem[]> = {}
+): string[] {
+  const sorted = [...order];
+  const itemsFor = (packageId: string): readonly DownloadItem[] => visibleItemsByPackage[packageId]
+    ?? (packages[packageId]?.itemIds ?? []).map((id) => items[id]).filter((item): item is DownloadItem => Boolean(item));
+  sorted.sort((a, b) => {
+    const serviceA = [...new Set(itemsFor(a).map((item) => item.providerLabel || (item.provider ? providerLabels[item.provider] : "")).filter(Boolean))].join(",").toLocaleLowerCase("de-DE");
+    const serviceB = [...new Set(itemsFor(b).map((item) => item.providerLabel || (item.provider ? providerLabels[item.provider] : "")).filter(Boolean))].join(",").toLocaleLowerCase("de-DE");
+    const comparison = serviceA.localeCompare(serviceB, "de");
+    return descending ? -comparison : comparison;
+  });
+  return sorted;
+}
 
 function computePackageProgress(pkg: PackageEntry | undefined, items: Record<string, DownloadItem>): number {
   if (!pkg) return 0;
@@ -4733,6 +4752,14 @@ export function App(): ReactElement {
         ? sortPackageOrderBySize(baseOrder, snapshot.session.packages, snapshot.session.items, nextDescending)
         : column === "hoster"
           ? sortPackageOrderByHoster(baseOrder, snapshot.session.packages, snapshot.session.items, nextDescending)
+          : column === "service"
+            ? sortPackageOrderByService(
+              baseOrder,
+              snapshot.session.packages,
+              snapshot.session.items,
+              nextDescending,
+              Object.fromEntries(downloadsViewCore.packageRows.map((row) => [row.package.id, row.items]))
+            )
           : sortPackageOrderByName(baseOrder, snapshot.session.packages, nextDescending);
     pendingPackageOrderRef.current = [...sorted];
     pendingPackageOrderAtRef.current = Date.now();
@@ -4745,7 +4772,7 @@ export function App(): ReactElement {
       setSnapshot((current) => ({ ...current, session: { ...current.session, packageOrder: serverPackageOrderRef.current } }));
       showToast(`Sortierung fehlgeschlagen: ${String(error)}`, 2400);
     });
-  }, [downloadsSortColumn, downloadsSortDescending, showToast, snapshot.session.items, snapshot.session.packageOrder, snapshot.session.packages]);
+  }, [downloadsSortColumn, downloadsSortDescending, downloadsViewCore.packageRows, showToast, snapshot.session.items, snapshot.session.packageOrder, snapshot.session.packages]);
 
   const clearDownloadQueue = useCallback((): void => {
     void performQuickAction(async () => {