Cleaned up sidebar redundancy sitewide
Every folder in the docs used to render twice in the sidebar — once as the parent, once as the index child. Fixed it everywhere at once.
The docs sidebar had been doing a quiet thing wrong for a while. Every folder was listed twice — once as the expandable parent, once as the "index" child below it. Body / Body. Mat / Mat. Skills / Skills. I hadn't noticed because the older sections only went two levels deep and the duplication blended in. The moment the Mat area landed with three levels of nesting, it became impossible to ignore.
Stripe, shadcn, Better Auth, Fumadocs's own docs all do this differently: the folder label is the link to the landing page. No duplicate child. The fix was a one-line change per meta.json — remove "index" from the pages array, let Fumadocs treat the folder itself as the destination. Did it sitewide in one pass.
While I was in there I also dropped the ---Foundations---, ---Graph---, ---Sources--- separator headers inside the Mat area. Too much ceremony for ten leaf pages. They can come back when the content justifies them.
Worth noticing: the bug had been there since the site launched. It took three levels of nesting to make it visible.