fix(a11y): label account QR code button

[AndyScherzinger]

• Resolves: NcButton accessibility warning fires twice on every logged-in page load (UserMenu, MainMenu) #60292

Summary

local version of #60616 for CI runs and merge

Summary

• Add an accessible label to the account menu QR code icon-only button.
• Add coverage for the QR code button accessible name.
• Add coverage that the app menu trigger buttons expose accessible labels.

Fixes #60292

Tests

• npx vitest run --project nextcloud-ui-legacy core/src/tests/components/AccountMenuProfileEntry.spec.ts core/src/tests/components/AppMenu.spec.ts
• npm run lint
• git diff --check origin/master...HEAD

Validated in a clean Docker container from a fresh nextcloud/server clone using node:24-bookworm.

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

[AndyScherzinger]

/backport to stable34

[AndyScherzinger]

/compile

[AndyScherzinger]

/backport to stable33

[backportbot]

The backport to stable33 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable33
git pull origin stable33

# Create the new backport branch
git checkout -b backport/61600/stable33

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 21adba71 bc58afec

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/61600/stable33

Error: Failed to check for changes with origin/stable33: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[susnux]

local version of #60616 for CI runs and merge

Should not be needed anymore any CI now works also on forks :)

[AndyScherzinger]

Neat, that I didn't know, but happy to hear 🎉

[AndyScherzinger]

/backport to stable33

[backportbot]

The backport to stable33 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable33
git pull origin stable33

# Create the new backport branch
git checkout -b backport/61600/stable33

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 21adba71 bc58afec

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/61600/stable33

Error: Failed to check for changes with origin/stable33: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.