Feature Request: Allow custom transition animation for popups

[videni]

Problem

Currently, vertical popups (TopPopup/BottomPopup) use a fixed .move(edge:) transition animation. There's no way to customize the transition to use different animations like .opacity, .scale, or combined transitions.

Use Case

In some UI designs, a fade-in/fade-out transition looks better than the default slide animation. For example:

• Tooltip-style popups that should appear/disappear smoothly
• Alert popups that benefit from a scale + opacity animation
• Custom popups that need to match the app's animation style

Proposed Solution

Add a .transition(_ value: AnyTransition) configuration method to LocalConfigVertical (which includes BottomPopupConfig and TopPopupConfig).

Example Usage

func configurePopup(config: BottomPopupConfig) -> BottomPopupConfig {
    config
        .transition(.opacity)  // Fade in/out instead of slide
}

// Or combined transitions
config.transition(.scale.combined(with: .opacity))