feat(500): one end-of-turn request - the completion-section check folds into the reply check

The Stop hook sent the finished reply twice: scribe_report_check.sh checked a
task-closing reply for the completion sections in shell and reported to
/report-check, and scribe_reply_check.sh sent the same reply to /reply-rules
for the rule hold. Now the reply goes once. When the turn closed a task the
hook adds the close count and ids, and the server runs the section check
(services/report_check, the same three patterns) beside the reply hold,
folding both into one reason.

The report_check adherence log is still written for every checked reply
(milestone 409's number). A section hold marks the session, so its rewrite is
sent back once with rewrite:true to record how it came out, and is never held.
The block reason carries the completion shape's one line and points at
list_reply_shapes rather than at the skill. #5496 (step 4 of milestone 500).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugin/hooks/scribe_shape_check.sh

@@ -10,7 +10,7 @@
 # words: the agent that built the code is the one participant who knows what
 # it is, and the end of the turn is the last moment that is still true.
 #
-# THE SAME DISCIPLINE AS scribe_report_check.sh, deliberately:
+# THE SAME DISCIPLINE AS the completion-section check in scribe_reply_check.sh:
 #   - it blocks only on a `reason` the instance returned, which it returns
 #     only for a block it RECORDED — an unconfigured or unreachable instance
 #     never stops a session, and every intervention is one the numbers see;