The core graph: document to word

The foundational graph under everything else: transform the document all the way down — sections, paragraphs, sentences, words — like an AST driven by the content, every level a node with an ID, because pointing at character 256 breaks the moment the document changes. Bold and links become span nodes, every distinct word gets a counted form node, the tree expands bit by bit from sharded files, the controls move into tabs, and the inspector shows everything known about a node.