require() in ESM module breaks in strict ESM environments

[vdg]

Description

The library uses require() in src/inline-renderer.ts:89 to avoid circular dependencies:

const { renderBlock } = require('./block-renderer.js');

However, require() is not available in strict ESM environments:

• Bun
• Deno
• Node.js with --experimental-vm-modules
• Bundlers in strict ESM mode

This causes a ReferenceError: require is not defined when rendering footnotes.

Steps to Reproduce

1. Use the library in Bun or Deno
2. Convert a Markdown document containing footnotes
3. Error is thrown

Expected Behavior

The library should work in all ESM-compatible environments.

Suggested Fix

Replace require() with dependency injection - pass renderBlock through the RenderContext object. This maintains the circular import avoidance while being fully ESM-compatible.