* fix(hotkeys): resolve combo letters via active XKB layout
Settings capture stores character tokens from GDK keyvals (e.g. alt+a),
but the Wayland/evdev path mapped letters to fixed US KEY_* codes. On
AZERTY that made Alt+A listen for the key labeled Q. Resolve letter
tokens through libxkbcommon for the active layout so recording and
listening agree.
Fixes#513
* refactor(hotkeys): slim layout-aware key resolution
Drop unused resolve helper, dual knobs, setxkbmap/localectl probes, and
redundant tests. Keep gsettings + libxkbcommon map and the AZERTY combo path.
* test(hotkeys): drop redundant AZERTY resolve-only case
Keep fire/no-fire combo coverage and the XKB fr map check.
* test(hotkeys): cover layout map detection and error paths
Raise patch coverage for layout_key_map / evdev_code_for_key so codecov
patch target (80%) is met.
