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

nisse-review/tests/test_review.py

@@ -342,6 +342,58 @@ def test_a_repository_whose_prs_cannot_be_listed_holds_up_no_other(
     assert '"intake.repo_failed"' in out.getvalue() and "a/empty" in out.getvalue()
 
 
+class Clock:
+    def __init__(self) -> None:
+        self.now = 1000.0
+
+    def __call__(self) -> float:
+        return self.now
+
+
+def test_a_new_head_waits_for_its_ci_to_finish(tmp_path: Path) -> None:
+    # Follow-up to #154: judged with CI's result, and off CI's GPU.
+    clock = Clock()
+    gitea = FakeGitea(repos={REPO: [pr()]})
+    head = pr().head_sha
+    gitea.ci[head] = "pending"
+    w = world(tmp_path, Scripted(*REVIEW), gitea, clock=clock)
+    assert w["scheduler"].round() is False  # pending: not yet
+    clock.now += 600
+    assert w["scheduler"].round() is False
+    gitea.ci[head] = "failure"  # finished: failing CI is worth a review too
+    assert w["scheduler"].round() is True
+    assert item(w).position == REVIEWED
+
+
+def test_ci_pending_too_long_is_reviewed_anyway(tmp_path: Path) -> None:
+    clock = Clock()
+    gitea = FakeGitea(repos={REPO: [pr()]})
+    gitea.ci[pr().head_sha] = "pending"
+    w = world(tmp_path, Scripted(*REVIEW), gitea, clock=clock, ci_wait_s=3600)
+    assert w["scheduler"].round() is False
+    clock.now += 3600
+    assert w["scheduler"].round() is True  # a stuck runner blocks nothing
+
+
+def test_no_ci_waits_only_a_grace_for_checks_to_appear(tmp_path: Path) -> None:
+    clock = Clock()
+    gitea = FakeGitea(repos={REPO: [pr()]})
+    gitea.ci[pr().head_sha] = "none"
+    w = world(tmp_path, Scripted(*REVIEW), gitea, clock=clock, ci_grace_s=120)
+    assert w["scheduler"].round() is False
+    clock.now += 120
+    assert w["scheduler"].round() is True
+
+
+def test_a_pr_waiting_on_ci_holds_up_no_other(tmp_path: Path) -> None:
+    clock = Clock()
+    gitea = FakeGitea(repos={REPO: [pr(7), pr(8, head_sha="c8")]})
+    gitea.ci[pr(7).head_sha] = "pending"
+    w = world(tmp_path, Scripted(*REVIEW), gitea, clock=clock)
+    assert w["scheduler"].round() is True  # 8, though 7 is older
+    assert (item(w, 7).position, item(w, 8).position) == (READY, REVIEWED)
+
+
 def test_a_configured_repository_it_cannot_read_is_left_out() -> None:
     gitea = FakeGitea(repos={REPO: []})
     out = io.StringIO()