OptionalassignedPending assignee, or undefined when none has been chosen.
OptionalcommentUnsaved edits to existing comments in this thread, keyed by comment id. A thread can hold an unsent reply and an in-progress edit at the same time, so these are tracked separately rather than sharing one editor state.
OptionaleditorSerialized contents of the unsent reply, or undefined when nothing has been typed.
A comment the user has typed but not committed — an unsent reply, an unsaved edit to an existing comment, or both at once (the reply compose box stays visible while editing an existing comment whenever it already has content). Held by the consumer rather than by the thread component, so it survives the component unmounting (a filter change does that routinely).