feat(seats): a pass's share of the windows by the run's effort, the weekly cutoff at 99 %

The 5-hour share of a running pass was a flat 0.25 points; it follows the
run's effort now, as the weekly share already did: 0.5 at max and any other
effort, 0.125 at xhigh - the pooled means of 5438 Opus 5.5 passes on 141
seat-runs (2026-10-12..15), rounded up. The weekly cutoff moves from 95 %
to 99 %: the weekly window is the budget the lenses run out of, and with
the running passes projected against the cutoff the last percent is spent
a pass at a time, not in a burst. REVIEW_GATES_LENS_COST_PCT and
REVIEW_GATES_LENS_COST_7D_PCT still override every effort.

process/prepush.md

@@ -261,7 +261,7 @@ drivers running and what they hold. The seat pool still places
 every process by its seat's projected 5-hour headroom
 (`REVIEW_GATES_LENS_COST_PCT`, `REVIEW_GATES_SEAT_MAX_UTIL`) — or, on an
 account whose 5-hour limit Anthropic has removed, by its weekly window
-under the 95 % cutoff — at most 128 passes per account, every driver's
+under the 99 % cutoff — at most 128 passes per account, every driver's
 counted (`REVIEW_GATES_OAUTH_CONCURRENCY`), and a pass
 launches only when its environment's instrument is free and it fits in
 free memory (How the passes share the stacks): the driver logs per gate