Replace 16 private SettingsNotifier fakes that only returned a fixed AppSettings with test/support/fixed_settings.dart. Mornye owner WIP tests and bespoke fakes are untouched.
The Material theme now draws its main surfaces with rounded Material
Symbols: navigation, player, mini player, queue, settings, sheets,
dialogs and shared controls. AppIcon maps legacy Icons to their symbol
and keeps outlined glyphs unfilled. Mornye keeps its original icons.
Icon buttons, text and filled buttons, dialog actions, sliders, the setup
FAB and indeterminate spinners use the Material 3 Expressive components.
Each wrapper falls back to the standard Flutter widget for Mornye, reduced
motion and custom sizing, so existing layouts and hit areas stay intact.
zarzet