YAML header convention: conflicts and Quarto version field collision

[MatMatt]

What we found

Comparing the YAML header convention across three sources in the repo revealed inconsistencies:

Three definitions, three formats

Source	Quotes	Field order	version	product-name	toc fields
Templates (_meta/templates/)	double	title first	placeholder text	present	absent
Editor-manual (DOCS/guidelines/)	double	title first	forbidden	required	absent
Actual DOCS/ files on main	none/single	category first	present	absent	present

PR #41 aligns the editor-manual and templates with actual practice.

version field collides with Quarto

Quarto defines version as a CLI version constraint (">= 1.1.0"), not document version. The CLMS library uses it for document version (2.3.0). This works in practice because fill_version.py processes it before Quarto renders, but it is a semantic collision.

Potential fix: rename to doc-version across all DOCS files + fill_version.py + strip_unknown_frontmatter.py.

category is a custom field

category is not part of the official Quarto schema. It is auto-completed by Quarto tools but has no documented behavior. CLMS relies on it for grouping/navigation.

What needs a decision

1. Should version be renamed to doc-version to avoid the Quarto collision?
2. Should toc/toc-depth/toc-title be documented as recommended or moved under format: html:?
3. Should product-name be removed from templates (PR Align YAML header convention across templates, editor-manual, and DOCS/ #41 does this) or kept?

cc @mckeea