- launch-keynctr.sh: builds renderer/electron main if missing, exports
KEYNCTR_ENABLE_GPU=1 (software rendering dies 'GPU process isn't
usable' on this Hyprland box), execs bundled electron with
--class=keynectr for WM_CLASS grouping.
- keynctr.desktop installed at ~/.local/share/applications/ (validated,
icon = public/icon.png, categories Utility, StartupWMClass keynectr).
- requestSingleInstanceLock: second launch focuses the existing window
(app.exit(0) in the doomed instance) instead of a duplicate shell
fighting the vault.
Verified via gtk-launch: 'keynectr | Keynctr' window maps; second
gtk-launch keeps exactly 1 window.
