Function renderMermaid

renderMermaid(
    code: string,
    container: HTMLElement,
    theme: MermaidTheme,
): Promise<SVGElement | null>
Render Mermaid source into the provided container and return the SVG element.
Parameters
- code: string
  Mermaid source text to render.
- container: HTMLElement
  Target element where the SVG is inserted.
- theme: MermaidTheme
  Mermaid theme name used for rendering.
Returns Promise<SVGElement | null>
Rendered SVG element, or null when rendering fails.

Remarks
This function loads Mermaid lazily on first use and sanitizes SVG output.
- Defined in content/mermaidRenderer.ts:22