braincheck

Typecheck and fix YAML frontmatter across a Markdown knowledge base / vault (Obsidian, docs, notes). Use when the user wants to validate frontmatter, enforce a metadata schema, find Markdown files with missing or malformed frontmatter, audit a vault's structure, add a new document type, or scaffold frontmatter onto files that lack it. Triggers: "check my frontmatter", "validate the vault", "enforce a schema on my notes", "what types of docs do I have", "fix missing frontmatter", "lint my Markdown metadata".