The gate at `getUnsubmittedReview` accepted `toolState.finalSummaryWritten`
as a valid Review exit, contradicting the post-failure error message which
already says Review's only valid exit is `create_pull_request_review`.
This let any caller that flipped `finalSummaryWritten` — including a
`task`-dispatched `reviewfrog` subagent calling `pullfrog_report_progress`
in violation of its prose-only read-only contract — silence the gate even
when the orchestrator never submitted a review.
Split per-mode: Review requires `toolState.review`, IncrementalReview keeps
the existing `||` (its post-failure message explicitly accepts
`report_progress` as a "no review warranted" exit). Test split mirrors the
new semantics.
closes#648
Colin McDonnell
d857e06731