Reusable composite action that counts codebase tokens using tiktoken
and generates a shields.io-style SVG badge. Color reflects context
window usage: green (<30%), yellow-green (30-50%), yellow (50-70%),
red (70%+). Badge includes hardcoded link back to repo-tokens.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
