data.toc is unavailable when running outside the Next.js runtime (via
bun scripts), so fragment links were all flagged as invalid. Parse
headings from raw markdown content instead, with a fallback chain:
data.toc -> getText('raw') -> readFile.
Also adds bunfig.toml with fumadocs-mdx bun preload plugin (recommended
by fumadocs docs for running scripts outside Next.js).
Reduces false positives from 134 errors to 90 real broken links.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Sushmithamallesh