Implement core JSX runtime for dsl-lite

[rafbcampos]

Description:

Implement the core JSX runtime functions that will be used by the esbuild JSX transformation. This includes createElement function and Fragment component that will serve as the foundation of our DSL compiler.
Tasks:

Tasks:

• Create jsx-runtime.ts file that exports createElement and Fragment
• Implement createElement function that constructs AST nodes from JSX
• Implement Fragment component for fragment syntax support
• Create type definitions for AST nodes, generators and type guards
• Unit tests

Technical Details:

/**
 * Create a JSX element (replaces React.createElement)
 * @param type - Element type (function, string, or special symbol)
 * @param props - Element properties
 * @param children - Child elements
 * @returns JSX element object
 */
export function createElement(type: any, props: any, ...children: any[]): JSXElement {
  // Process children to flatten arrays and filter nulls
  const processedChildren = children.length > 0
    ? children.flat().filter(child => child != null)
    : [];

  const combinedProps = props ? { ...props } : {};

  if (processedChildren.length > 0) {
    combinedProps.children = processedChildren.length === 1
      ? processedChildren[0]
      : processedChildren;
  }

  return {
    type,
    props: combinedProps,
    $$typeof: Symbol.for('jsx.element')
  };
}

export function Fragment(props: FragmentProps) {
  return props.children;
}