The #921 selector change and the duplication gate both first ran against
this branch after the merge made it MERGEABLE: assembly-surfaces still
queried the retired data-sample="todo-row" hook (the composed TodoRow
carries ToolRow's data-tool attribute instead), and the redesigned
QuestionComposer duplicated the custom-draft onChange/onKeyDown pair
across its inline input and optionless textarea. The spec now anchors on
data-tool="todo_write", and the composer shares one draftCustom /
continueFromCustom handler pair (Enter continues, Shift+Enter stays a
newline, IME composition stays inert).