Build `prerequisite` Rune

Summary

Declares dependencies between content pages. "Complete X before starting this lesson." Themes can render these as a learning path or dependency graph.

Attributes

Name	Type	Default	Required	Description
`path`	String	—	Yes	Path to the prerequisite page (relative URL)
`label`	String	—	No	Display label (defaults to the target page's title)
`required`	Boolean	`true`	No	Whether this is a hard requirement or a recommendation

Content Model

Self-closing tag (no children). All data comes from attributes.
Multiple {% prerequisite %} tags can appear on a page.

Transform Output

typeof: Prerequisite
Tag: <a> or <div>
Properties: path, label, required

Implementation Tasks

Create schema in runes/learning/src/tags/prerequisite.ts
Add RuneConfig entry in runes/learning/src/config.ts
Write CSS in packages/lumina/styles/runes/prerequisite.css
Import CSS in packages/lumina/index.css
Implement cross-page dependency graph collection via @refrakt-md/learning package's register() pipeline hook
Write tests in runes/learning/test/tags/prerequisite.test.ts
Create inspector fixture

Implementation Notes

The rune itself is simple — the complexity is in the build pipeline integration. The content pipeline collects all prerequisite declarations and builds a dependency graph. Themes can render this as a progress tracker, learning path visualization, or simple prerequisite list.