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_defs.sh

@@ -135,8 +135,8 @@ scribe_json_flat_lines() {
 # Cheap by construction, because it runs on every prompt: the last 512 KB only,
 # and grep narrows to assistant records carrying a text block BEFORE anything is
 # parsed — a transcript is mostly tool results, and parsing those in awk is the
-# multi-second cost scribe_report_check.sh already measured. Fixed strings with
-# UNESCAPED quotes can only match at a record's own top level (see that hook).
+# multi-second cost the completion-report check measured (#4107). Fixed strings
+# with UNESCAPED quotes can only match at a record's own top level.
 # A sidechain is a subagent talking, not this session, so it is skipped.
 scribe_recent_context() {
   [ -n "${1:-}" ] && [ -f "$1" ] || return 0