nisse-review: a review refused for an open point posts once the point is answered

On #166 the reviewer called post_review with two points unanswered, was
refused, answered them, then only skipped already-answered points until the
40-turn cap: the review went out as partial, its summary lost. A refused
ending call is now held, and the driver ends the run with it as soon as the
last point is settled (a new due hook in nisse-core's driver; nisse-dev
doesn't use it). A held call that is wrong for another reason by then
(sign_off over drafted comments) is left to the model. With nothing open,
reply and skip say which tool ends the run.

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

docs/Development-Plan.md

@@ -683,8 +683,11 @@ of earlier points, replies on threads, the round cap and its reset, `stop` and
   can't be listed, and its earlier points with what was said on their lines.
 - **Replies:** `reply` answers a point where it was made (inline on its line,
   else quoting it), `skip` leaves it with a reason, `done` ends; every point is
-  answered or skipped before a run may end. Each reply carries its point's key,
-  so a run re-done after a crash answers nothing twice.
+  answered or skipped before a run may end. An ending call refused for that is
+  held, and goes ahead as soon as the last point is settled, rather than left
+  to the model to make again (on #166 it didn't, and looped to the turn cap).
+  Each reply carries its point's key, so a run re-done after a crash answers
+  nothing twice.
 - **Sign-off:** `sign_off` posts a short review when there is nothing to raise;
   while it stays happy, a later review offers `still_happy`, which posts nothing
   (operator: no repeated LGTMs).