fix(downloads): harden queue and lifecycle synchronization

Serialize queue controls, make multi-item moves atomic, await stale enqueue cleanup, and guard late media and progress events. Add deterministic table sorting and regression coverage for worst-case lifecycle races.

src/utils/downloadTableSorting.test.ts

@@ -0,0 +1,60 @@
+import { describe, expect, it } from 'vitest';
+import type { DownloadItem } from '../bindings/DownloadItem';
+import {
+  parseDownloadEta,
+  parseDownloadSize,
+  sortDownloads,
+  type DownloadSortConfig
+} from './downloadTableSorting';
+import { redactDownloadForPersistence } from './downloads';
+
+const item = (id: string, overrides: Partial<DownloadItem> = {}): DownloadItem => ({
+  id,
+  url: `https://example.test/${id}`,
+  fileName: id,
+  status: 'queued',
+  category: 'Other',
+  dateAdded: '2026-07-14T00:00:00.000Z',
+  ...overrides
+});
+
+const sortedIds = (downloads: DownloadItem[], config: DownloadSortConfig): string[] =>
+  sortDownloads(downloads, config).map(download => download.id);
+
+describe('download table sorting', () => {
+  it('compares human-readable sizes by bytes instead of their leading number', () => {
+    expect(parseDownloadSize('1 MB')).toBe(1024 ** 2);
+    expect(sortedIds([
+      item('one-mb', { size: '1 MB' }),
+      item('900-kb', { size: '900 KB' }),
+      item('two-mb', { size: '2 MB' })
+    ], { column: 'Size', direction: 'asc' })).toEqual(['900-kb', 'one-mb', 'two-mb']);
+  });
+
+  it('supports clock and unit ETA values and keeps unknown values last', () => {
+    expect(parseDownloadEta('01:02:03')).toBe(3723);
+    expect(parseDownloadEta('2m 5s')).toBe(125);
+    expect(sortedIds([
+      item('unknown', { eta: '-' }),
+      item('long', { eta: '2m' }),
+      item('short', { eta: '10s' })
+    ], { column: 'ETA', direction: 'asc' })).toEqual(['short', 'long', 'unknown']);
+  });
+
+  it('sorts descending on the second click without reverting to an unsorted list', () => {
+    const downloads = [item('b', { fileName: 'Beta' }), item('a', { fileName: 'Alpha' })];
+    expect(sortedIds(downloads, { column: 'File Name', direction: 'asc' })).toEqual(['a', 'b']);
+    expect(sortedIds(downloads, { column: 'File Name', direction: 'desc' })).toEqual(['b', 'a']);
+  });
+
+  it('does not persist volatile progress fields', () => {
+    const persisted = redactDownloadForPersistence(item('volatile', {
+      fraction: 0.75,
+      speed: '1 MB/s',
+      eta: '10s'
+    }));
+    expect(persisted.fraction).toBeUndefined();
+    expect(persisted.speed).toBeUndefined();
+    expect(persisted.eta).toBeUndefined();
+  });
+});