- Remove all uses of deprecated highlight() method in CustomMenuWindow
- Consistently use state property for NSStatusBarButton management
- Update StatusBarMenuManager to reset button state when menu state is .none
- Fix concurrency issues in CustomMenuWindow frame observer
- Ensure button state is properly managed throughout menu lifecycle
This fixes the issue where the button could display inconsistent visual states
or get stuck due to conflicting approaches between highlight() and state.
- Create custom SideRoundedRectangle shape with flat top/bottom borders
- Apply custom shape to both SwiftUI background and NSWindow mask layer
- Update CustomMenuContainer to use the new shape for consistent styling
- Maintain rounded corners only on left and right sides as requested
This gives the menu bar dropdown a more integrated appearance with the
menu bar while keeping the modern rounded aesthetic on the sides.
