fix(kivex-react): support className and SVG props

[Joseph4sure]

✅ Summary

This PR adds full support for className, style, onClick, and any other standard SVG/HTML props to all kivex-react icons.
It also updates the playground with a comprehensive demo to showcase the new capabilities.

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What changed

Library (kivex-react)

• Updated IconBase to spread all remaining props (...rest) onto the underlying <svg> element.
• All generated icons now accept:
  • className – for custom CSS (including Tailwind)
  • style – inline styles
  • Event handlers like onClick, onMouseEnter, onMouseLeave
  • ARIA attributes (aria-label, role, etc.)
  • Data attributes (data-*)
  • Any other valid SVG or HTML attributes
• Regenerated all icon components to include the updated template (npm run generate).
• Type definitions now reflect the extended props.

Playground (react-playground)

• Added a dark container background (#333333) with a title.
• Rendered 6 icons (Home, Heart, Star, Settings, Users, Folder) in a responsive grid.
• Each icon demonstrates different props:
  • className with custom CSS hover effects and animations
  • style for inline overrides
  • onClick / hover events
  • aria-label and data-* attributes
• Included comprehensive CSS with transitions, animations, and focus styles.

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Why

Before this change, icons were limited to size, color, and strokeWidth – they couldn't be styled with CSS classes, respond to click events, or be made accessible.
This PR makes kivex-react icons truly flexible and drop‑in replacements for raw <svg> elements, enabling:

• Seamless integration with CSS frameworks (Tailwind, Bootstrap, custom CSS)
• Full interactivity (clicks, hovers, focus)
• Better accessibility (ARIA labels, roles, keyboard navigation)
• Easier testing and debugging (data attributes)