[Jason3S]

Summary

Builders, element/ and the template helpers now build and read Markdown nodes through functions in mdast/, such as strongNode(children), instead of writing node objects by hand. This is one step toward keeping all tree code in that one folder.

Waits on the parser move: the build fails until the parser is in mdast/. Other layers now name node types from mdast/index.ts, so the public type bundle reaches the folder's declarations:

• The folder's index still re-exports htmlEntityFromMarkdown for template/parse.ts.
• Its type comes from mdast-util-from-markdown, whose own types augment micromark-util-types.
• The bundle keeps that augmentation, and the dependency check stops the build.

Once the parser is in mdast/, the extension is private to the folder, and the build passes. A local trial confirmed this: dist/index.d.ts came out as on main.

Node constructors and readers (mdast/nodes.ts)

• One constructor for each node type the other layers build, such as paragraphNode, headingNode, listNode and tableNode.
• listNode numbers the list when given a start. listItemNode makes a task when given checked. tableNode takes the content of each cell, row by row.
• Readers for what other layers checked by hand: frontmatterOf, withoutFrontmatter and paragraphContent.
• Other layers name node types such as RootContent through the folder's index, not from mdast.

Node helpers moved into the folder

• textNodes, stringNodes and joinLines go to mdast/text.ts, and inLists to mdast/lists.ts.
• isFormatting moves from blanks.ts to nodes.ts.

The mdast augmentations, in one file that nothing imports

The four declare module 'mdast' blocks move to mdast/customNodes.ts. In declaration files they're side effects, so a type import from the folder pulled them, and all of @types/mdast, into the public types. In a file with no importers, they apply only when the package's own source is type-checked.

Layer test

src/layers.test.ts fails when a file outside mdast/ imports a tree package: mdast, remark-*, unified, unist-*, micromark* or mdast-util-*. It lists the five files that still do, and the next steps empty that list.