feat(keybinds): add keybind for PAM U2F on lock screen

[nozsh]

Description

Adds keybind to trigger PAM U2F authentication on lock screen via Ctrl+Q

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that changes existing behavior)
• Refactor / internal cleanup
• Documentation
• Other

Checklist

• My code follows the conventions in CONTRIBUTING.md
• I have tested my changes locally
• New user-facing strings are wrapped in I18n.tr() with translator context, reusing existing terms where possible
• Go changes: ran make fmt, added/updated tests, make test passes, and go mod tidy is clean
• QML changes: ran make lint-qml with no new warnings
• I have opened a corresponding pull request in dlx-docs to document any new behaviors: https://github.com/AvengeMedia/DankLinux-Docs

[Purian23]

Thanks for the PR, a keyboard option is warranted. A few items:

We can't merge a hardcoded Ctrl+Q in this sense. The passkey button already calls startForAlternativeAuth(), and compositor keybinds don't reliably work on the lock screen anyway.

Please rework to:

• Shared helper (e.g. triggerSecurityKeyUnlock()) used by both the button and keyboard handler, gated by canStartSecurityKeyUnlock()
• Lock Screen setting for the shortcut or a documented default with a UI hint
• Key handler inside the existing Ctrl-only modifier block

Happy to re-review once that's in.

[nozsh]

Thanks for advice. Done, I hope this is exactly what you meant.

In settings it looks like this:

[Purian23]

Thanks, looks good. I added a few QOL adjustments and the missing settings json. Should be good to go.