Add Liquid glass card

[Katotodan]

Notes for Reviewers
This PR introduces a new LiquidGlass UI primitive to the Sistent library. The component provides a reusable “liquid glass / glassmorphism” effect that can be used as a container for content while preserving readability and visual depth.

Features

1. Frosted glass effect using backdrop-filter (blur + saturation)
2. Optional “overLight” mode for light backgrounds
3. Optional shadow toggle (showShadow)
4. Customizable:

• blurAmount
• saturation
• cornerRadius
• padding

Implementation Notes

• The glass effect is isolated in a dedicated backdrop layer to avoid blurring child content.
• Defaults are provided to ensure the component works out-of-the-box while remaining customizable.

This PR fixes #1238

Signed commits

• Yes, I signed my commits.

[Katotodan]

While developing, I tried this component inside a simple react app to see the output.
Here is the demo

Screen.Recording.2026-02-11.at.16.58.03.mov

Here is a screenshot of code for the above react app visualization.

[Katotodan]

I have also tried it with layer5 website locally.

Screen.Recording.2026-02-11.at.17.02.10.mov

Here is a portion of layer5 main page code with the LiquidGlass component on it

The zIndex is customized (and other properties as well).

[leecalcote]

We have something similar on www.kanvas.new now., so the concept is viable.