release: prepare v2.0.18 interface and reset reliability update

Preserve package progress and history across immediate cleanup, make extraction resets wait for all post-processing tasks, and keep archive diagnostics out of compact status cells. Rework account creation and settings selectors, improve context-menu placement, remove accidental row dragging, and expand regression coverage for the corrected workflows.

src/renderer/views/downloads/DownloadsView.tsx

@@ -70,9 +70,6 @@ export interface DownloadsViewActions extends DownloadsTableActions {
   onClearAll: () => void;
   onToggleAllPackages: () => void;
   onShowAllPackages: () => void;
-  onPackageDragStart: (packageId: string) => void;
-  onPackageDrop: (packageId: string) => void;
-  onPackageDragEnd: () => void;
 }
 
 const filters: Array<{ id: DownloadSidebarFilter; label: string }> = [
@@ -152,10 +149,7 @@ function packageRows(model: DownloadsViewModel, actions: DownloadsViewActions):
       gridTemplate={model.gridTemplate}
       key={row.package.id}
       packageSpeedBps={model.packageSpeedBps[row.package.id] ?? 0}
-      onDragEnd={actions.onPackageDragEnd}
-      onDragStart={actions.onPackageDragStart}
-      onDrop={actions.onPackageDrop}
-      row={row}
+      row={row}
       selectedIds={model.selectedIds}
       selectedVersion={model.actionableSelectedIds.length}
       sessionRunning={model.running}