wc-captain-ladder

Computes the optimal rolling-captaincy LADDER across a matchday's staggered kickoff sequence — the ordered captain candidates, the explicit bank-or-switch rules at each kickoff, and the captaincy_uplift that wc-fitness-eval folds into raw_xEV. Because the armband doubles the round's points AND can be MOVED during the round to a player who has not yet kicked off, captaincy EV is the expected value of the best outcome reachable by switching across the sequence — not a naive 2x of the top xEV player. Call from wc-matchday-tactician (to write MB2 of the matchday plan), from the strategists (to value a candidate's captaincy when building a matchday plan), and from wc-fitness-eval (which consumes captaincy_uplift). Returns the ladder, the switch thresholds, and the uplift against a stated baseline; the ladder is moot under the Maximum Captain chip (value = max of candidates).