Responding to ds-review-bot round 2 on #658 (three critical findings, one
warning — all rooted in the pump/commit split racing ordered stages):
- ONE driver lane now owns every ordered stage: the start append, prepare
(pre-execute/guards), and the head-of-line commit (post-execute, context
deferral, settle append). start() is awaited before the next entry can
start, so concurrent submissions can no longer run pre-execute pipelines
concurrently; only the around-dispatch/body stage overlaps, matching the
native loop's fillPool sequencing.
- An exclusive call's barrier now holds through its COMMIT: later starts
wait for the exclusive pipeline (post-execute included) to finish, the
native exclusive-group semantics.
- drainDispatches() awaits the driver run itself, so a commit already
mid-flight when the program returns is drained before run_code closes
the turn — the settle event and deferred contexts land inside it.
- maxParallelSubCalls is resolved and validated at construction (positive
integer), so direct construction can no longer wedge the pool with 0.
New tests: overlapping-submission ordered-prepare, barrier-through-commit,
drain-mid-commit, cap rejection. 96 keyless snapshots replay unchanged;
Agent Note updated (both languages).