Renderer #

The renderer owns presentation and browser interaction, not the document model. It translates user input into core operations and projects the resulting document back into the DOM.

Input, projection and selection mapping stay together because DOM changes can disturb caret positions and active composition. During IME composition, the browser needs temporary control of the composing DOM; that temporary state must not become a second document model or undo history.

The surrounding application UI stays separate from the editable surface so UI updates do not interfere with native text interaction. Privileged operations go through the desktop bridge rather than directly to the filesystem.