a11y(QueueItem): align Cancel/Retry button tooltips with aria-label (sibling to #945)

[Salem874]

Problem

PR #945 (shipped in #947) aligned the `title` attribute with the `aria-label` for three QueueItem buttons (Retry-without-Wrapper, Open File, Open Folder) so sighted hover-tooltips and screen-reader announcements match.

Two sibling buttons in the same file were missed:

• src/components/download/QueueItem.tsx:617 — Cancel button has `title="Cancel"`; should be "Cancel download" to match the verbose pattern the other four buttons set.
• src/components/download/QueueItem.tsx:633 — Retry button has `title="Retry"`; should be "Retry download".

Fix

Two-line edit:

```tsx
// 617
title="Cancel download"

// 633
title="Retry download"
```

If aria-label is missing on these two, add it with the same string. Mirrors the #945 pattern.

Verification

• Existing `QueueItem.test.tsx` passes unchanged.
• VoiceOver / NVDA tab through Queue items — Cancel + Retry now announced with the full "…download" suffix.