Make shortcuts configurable

[ottsch]

Context: User report — the "@" shortcut does not work with German keyboard layout in Chrome on Windows 11.

Refined description:
Allow users to configure keyboard shortcuts (e.g. the "@" toggle) so that the extension works correctly across different keyboard layouts and locales.

[sm17p]

I'm so sorry. I'll try to push an update by the end of this month with a few more things, will ping here

[sm17p]

I'm not using any library right now. I think hotkey libs handle modifier combination maybe that might help to

[sm17p]

Triage pass complete.

Proposed direction:

• Move shortcuts into user settings with a keyboard-capture UI and per-action bindings.
• Persist normalized KeyboardEvent.code plus modifier set rather than locale-dependent printable characters.

Research notes:

• event.key varies by keyboard layout (e.g. German @ entry paths), while event.code is layout-stable for physical keys.
• Conflict detection and reset-to-default will prevent broken keymaps.

Implementation slice:

1. Add shortcut settings schema in storage.
2. Add settings UI to rebind actions.
3. Update shortcut handler to match normalized binding and ignore editable contexts.

Definition of done:

• Same action can be rebound on non-US keyboard layouts.
• Existing default shortcuts still work after migration.