fix: allow Enter on public share Download link

[kristian-zendato]

• Resolves: [accessibility] public share: cannot use "download" button with keyboard only #62245

Summary

On public shares, the header Download control is an <a> that can be focused with the keyboard, but Enter did not start the download.
Cause: each FileEntry registered an Enter hotkey with prevent: true / stop: true. useHotKey always called preventDefault before the callback, so Enter was cancelled even when the row was inactive and did nothing.
Change: only call preventDefault / stopPropagation inside triggerDefaultAction when the row is active. Browser default activation of the Download link works again.
Added a Cypress regression test that focuses Download and presses Enter.

TODO

• Fix Enter hotkey so it does not block other focused controls
• Cypress coverage for keyboard download on public share
• Confirm manual keyboard check on a live public share (Enter on Download)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[susnux]

/backport to stable34

[susnux]

/backport to stable33

[susnux]

looks good, but ESLint needs to be resolved