Returns whether an open-file progress event represents a terminal state.
CONVERSION completes with subStage END. After openUri finishes parsing,
data-model also emits a trailing FETCH_FILE event at 100% with
subStageStatus END but no subStage — that must hide the overlay too.
Returns whether an open-file progress event represents a terminal state.
CONVERSION completes with subStage
END. AfteropenUrifinishes parsing, data-model also emits a trailing FETCH_FILE event at 100% with subStageStatusENDbut no subStage — that must hide the overlay too.