Large JSON virtualization and lazy loading

[parsapanahpoor]

• Issue Title: Optimize rendering for large JSON documents (virtualization)
• Description:
  Add performance optimizations (such as virtualization and/or lazy loading) to handle large JSON documents without freezing the UI. Only visible portions of the tree should be rendered at any time.
• Tasks:
  • Identify performance bottlenecks with large JSON samples.
  • Implement virtualization or incremental rendering for tree nodes.
  • Optionally add a soft limit or warning for very large inputs.
  • Ensure scrolling and interaction remain smooth.
  • Add a demo page with a large JSON file.
  • Document performance considerations and any configuration options.