Proportional study allocation — preview acceptance record (2026-09-07)

Acceptance evidence for #3269 gathered in the PR #3327 preview environment, where proportionalStudyAllocation is enabled for the API, Project Management and Web services only. Staging and production remain off. Membership lifecycle (#2271), shared authorization authority (#3251) and performance qualification (#3252) are recorded separately when they land.

Merged-code checkpoint

Item	Value
main tip under test	pending
Included PRs	#2991, #3211, #3212, #3213, #3228, #3267
Generated-contract check	pending
API / Core / Mongo / Web validation	pending

Checklist

#	Item	Method	Identities	Observed	Verdict
1	Assigned next-study stream stays inside each reviewer's buckets	pending
2	Out-of-share direct study GET denied (404) before side effects
3	Out-of-share session PUT denied (404) before side effects
4	Bounded counts and paging on my-studies and progress
5	Saved-work resume for the same reviewer and stage
6	Stale/invalid configuration and zero-share reviewer fail closed
7	Flag off restores legacy behaviour without deleting saved work

Release decisions

Environment	Decision	Version	Date
Preview (PR #3327)	Authorised by repository owner	pending	2026-09-07
Staging	Withheld
Production	Withheld