Build `math` Rune

Summary

Mathematical notation rendered from LaTeX/KaTeX syntax. Supports both inline and block (display) mode. Aliases: equation, formula. This is a core rune.

Attributes

Name	Type	Default	Required	Description
`display`	Boolean	`true`	No	Block display mode (centered, full-width) vs inline
`label`	String	—	No	Equation label for cross-referencing

Content Model

Text content inside the tag is treated as raw LaTeX/KaTeX source — not parsed as Markdown
Similar pattern to {% diagram %} treating content as Mermaid source

Transform Output

typeof: Math
Tag: <div> (display) or <span> (inline)
Properties: source (the raw LaTeX string), label

Implementation Tasks

Create schema in packages/runes/src/tags/math.ts — raw source extraction pattern (like diagram)
Add RuneConfig entry in packages/runes/src/config.ts
Write CSS in packages/lumina/styles/runes/math.css
Import CSS in packages/lumina/index.css
Implement rendering: build-time KaTeX transform (preferred, like Shiki for code) or web component fallback
Write tests in packages/runes/test/tags/math.test.ts
Create inspector fixture
Run CSS coverage tests

Implementation Notes

Rendering strategy mirrors the Diagram rune — either a build-time transform (like @refrakt-md/highlight does for code blocks) or a web component that initializes from the source attribute. Build-time is preferred for performance and SSR.