Make compact liii toolbar and fix empty strip when use_native_menubar is enabled

[AnvarAtayev]

Two related UI improvements for the liii/liii-night themes on macOS:

1. Compact toolbars - reduce toolbar row height from 36 px to 28 px and tighten button padding, giving a denser, more native-feeling toolbar layout.
2. Fix empty white strip with native menu bar - when use_native_menubar is enabled, the menuToolBar container remained visible at full height even though its content moved to the system menu bar.