Create Neo.component.Markdown for Encapsulated Markdown Rendering

Implement a dedicated Neo.component.Markdown component to encapsulate Markdown rendering logic and styling, promoting reuse and consistency across LivePreview and ContentComponent.

Scope:

1. Create src/component/Markdown.mjs:

   • Config: ntype: 'markdown', reactive value_ (markdown string).
   • Logic: Uses MarkdownRenderer internally. When value changes, delegates rendering to the renderer.
   • Lifecycle: Delegates destroy() to renderer.destroyComponents().
   • Styling: Move styles from ContentComponent.scss to a new src/component/Markdown.scss (or similar shared location) and apply them here.

2. Refactor LivePreview.mjs:

   • When language is 'markdown', instantiate Neo.component.Markdown inside the preview container instead of using the renderer directly on the container.
   • Bind the editor value to the markdown component's value.

3. Refactor ContentComponent.mjs:

   • Extend Neo.component.Markdown instead of Neo.component.Base.
   • Inherit the rendering and styling logic.
   • Retain specific Portal logic (fetching, routing, intersection observer).

Goal: Decouple styling from the view and logic from the renderer, creating a self-contained Markdown component that can be used anywhere (e.g., LivePreview, Dashboards).

Note: This ticket focuses on the component creation and integration. Consolidating logic from MarkdownRenderer into the component itself is out of scope for this task and will be considered later.