nisse-review: a retried or recovered review keeps its head's CI wait

From nisse-review's own review of #155: a failed run, a posted one and
crash recovery rebuilt the item without seen_at, so a retry skipped the
CI wait. seen_at now carries through, renewed when the head moved during
the review. Also: a test for checks Gitea can't report, and the example
config lists ci_wait_s and ci_grace_s.

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

nisse-review.example.yaml

@@ -35,6 +35,7 @@ gitea:
 #     notes: ro
 
 # tuning:                             # docs/Tuning-Guide.md
-#   review: {poll_s: 60, max_turns: 40, diff_chars: 60000, attempts: 2}
+#   review: {poll_s: 60, max_turns: 40, diff_chars: 60000, attempts: 2,
+#            ci_wait_s: 3600, ci_grace_s: 120}
 #   expert: {consult_budget: 3}
 #   context: {keep_recent_turns: 6, safety_margin: 0.1}