Frontmatter has no machine-readable description. Add packages/content/frontmatter.schema.json, publish it on the versioned routes BUG-004 built, and make Frontmatter derive its documented members from it.
a2a0a00aface3245feb60Editors gain inline validation and autocomplete for frontmatter in .md files, which nothing provides today. That is the first benefit; feeding the generated reference is the second.
Writing it also forces four fields into the open. type, id, created, and modified are read by page-entities.ts and timestamps.ts through the interface's [key: string]: unknown index signature — they are undeclared and undocumented. type is the field that drives the entire entity registry: it is what makes /runes/rune-catalog work, and an author cannot currently learn it exists from the page that claims to list frontmatter fields.
packages/content/frontmatter.schema.json describes every frontmatter field refrakt itself consumestype, id, created, and modified are declared, with descriptionsicon, tint, tint-mode, and tint-lock are declaredFrontmatter no longer hides consumed fields behind the index signatureFrontmatter interface, as config-schema.test.ts does for the config schemadescriptionReuse the machinery already in place. site/src/lib/schema-versions.ts enumerates versions and stamps $id; adding a third schema is a SCHEMA_FILES entry plus two routes. The $id in the source file stays unversioned so the packaged copy cannot go stale, matching the other two.
Model the drift test on config-schema.test.ts — extract the interface members from packages/content/src/frontmatter.ts and assert coverage both ways. That test found two discrepancies nobody had spotted by hand; the same approach should be pointed at this interface from the start rather than retrofitted.
The index signature is a feature, not an oversight. Runes and pipeline hooks read arbitrary author fields. The schema describes what refrakt consumes; it does not close the set, and it should not set additionalProperties: false.
Completed: 2026-09-10
Branch: claude/content-author-docs-org-vps1un
packages/content/frontmatter.schema.json — 18 properties, every one with a description. Open set: no additionalProperties: false.
packages/content/src/frontmatter.ts — type, id, created and modified declared, each with a note naming the consumer that reads it. The index signature keeps its own comment explaining that it is deliberate.
site/src/lib/schema-versions.ts — packageDir(name) replaces transformPackageDir(), and SCHEMA_FILES carries a package per schema. The frontmatter schema ships in @refrakt-md/content, not transform.
Two routes mirroring the existing pair, plus files widened in packages/content/package.json so the schema is published.
packages/content/test/frontmatter-schema.test.ts — 9 tests: drift both ways, every property described, the four formerly-hidden fields asserted by name, and validation cases including the open set and the tint: null reset.
docs/configuration/schema.md — a table of all three published schemas and an editor-configuration snippet for validating frontmatter.
$id is stamped per version, and the full v0.11→current range is served.files field would have silently omitted the schema from the published package — transform lists its two schemas explicitly and content listed only dist.