feat: add TubesBackground component and types

[AshishDev-16]

This PR introduces a brand new, highly interactive 3D animated TubesBackground component to the MagicUI library using threejs-components.

Changes

• New Component: Added TubesBackground for gorgeous, customizable, animated 3D background effects.
• Interactivity: Built-in click interactions to randomize the abstract tube lighting and color gradients dynamically on the canvas.
• Demo & Registry: Created a fully featured demo (tubes-background-demo.tsx) and successfully registered the component for the CLI.
• Documentation: Wrote comprehensive MDX documentation (tubes-background.mdx) with clear usage instructions and configured it in the docs sidebar.
• Types: Ensured strict TypeScript compliance by adding the necessary declaration types (threejs-components.d.ts).

Motivation

MagicUI aims to provide the best modern, dynamic web interface components out there. Adding this abstract geometric 3D background gives users a premium, high-end aesthetic option right out of the box. It feels completely alive and responsive to clicks, giving any landing page or hero section an immediate "wow" factor.

Breaking Changes

None! This is purely a neat, backwards-compatible new component addition.

Screenshots / Videos

Screen.Recording.2026-03-18.141843.mp4