Review fix (ds-review-bot on #623): the per-session-modes section still
described first-turn stamping — superseded by the header baseline — and its
formula lacked the middle rung. The formula now reads own post-seed knob
events ?? inherited SessionHeader baseline ?? composition default, and the
paragraph describes the synchronous capture into the creation-time header
with no first-turn timing window. Chinese counterpart updated in the same
commit.
8c106017d9