nisse-review: a new head's review waits for its CI

A review judges the CI result (R1), so a new head's review now waits while
its checks are pending, and starts once they finish, passed or failed. It
also keeps reviews off a GPU that CI is using: #154's first review ran
beside CI's end-to-end job and took about 30 minutes.

- Pending: waits up to tuning.review.ci_wait_s (1 h), then reviews anyway.
- No checks: waits tuning.review.ci_grace_s (2 min) for them to appear,
  then reviews.
- A PR waiting on CI holds up no other: the oldest settled one goes first.
- The head's first sighting is kept on the item (seen_at).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

docs/Architecture.md

@@ -888,7 +888,9 @@ else) towards better changes.
 - **A work item per PR,** scoped to its repository (L1). It closes when the PR
   merges or closes.
 - **What starts a run:** the PR becoming ready, a new push, or a new comment or
-  review on it.
+  review on it. A new head's review waits for its checks to finish (passed or
+  failed), so it is judged with the CI result and stays off a GPU that CI is
+  using; up to a tuning limit, and not at all where there is no CI.
 - **The first review** is given the PR (title, description, its commits and diff,
   its comments, and the issue it closes); the reviewer reads the rest as it needs
   it (R3).

docs/Tuning-Guide.md

@@ -638,3 +638,25 @@ reads file by file.
 
 Failed review runs on one PR, at one head, before the reviewer says on the PR
 that it couldn't review it, and stops trying until the next push.
+
+### `tuning.review.ci_wait_s` — default 3600
+
+How long a new head's review waits while its checks are pending. A review
+judges the CI result (R1), and waiting keeps it off a GPU that CI is using
+(the `nisse` project's end-to-end tests). Finished checks, passed or failed,
+end the wait; after this long it reviews anyway and the CI result reads as
+pending.
+
+- **Too low:** reviews run beside CI, slower on a shared GPU, without its result.
+- **Too high:** a stuck runner delays reviews that long.
+- **Deciding:** a little longer than the repository's slowest CI run (the full
+  end-to-end suite takes 25 minutes or more).
+
+### `tuning.review.ci_grace_s` — default 120
+
+How long a new head with no checks at all waits for some to appear: Gitea
+Actions reports a push's checks a moment after it. Past this, a repository
+without CI is reviewed at once.
+
+- **Too low:** a review starts before CI has reported, and runs beside it.
+- **Too high:** repositories without CI wait that long for every review.