feat(500): reporting-back becomes the long-form reference behind the delivered shapes

The reply shapes are server product now, delivered at their moments, so the
skill stops restating them. Gone from it: the "Every reply" list, the
per-kind tables, and "The operator's own shapes come first" (preferences
arrive beside the shape on the same moments). It opens by saying where the
shapes come from (list_reply_shapes, the delivered core's header) and keeps
the reasoning: sections chosen not filled, a settled decision acted on,
placement from the record, who decides what, the assumptions an option
carries, the completion report worked in full, and the second pass. 13.5k to
10.7k characters.

The core gains the Finding kind the skill's table carried (2,150 of 2,200).
Tests follow the content: the kind and Approval-row pins move to the shapes,
a new test holds the worked example and the completion shape to the same
sections, and the guidance-ownership registry reads the delivered shapes as a
surface, owning the preference-wins and length topics there. using-scribe
points at the delivery and list_reply_shapes. #5496.

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

plugin/skills/using-scribe/SKILL.md

@@ -263,9 +263,11 @@ Two constraints on *how* that's achieved:
    order you did things in: which task or milestone it belongs to, what now
    works, what needs them, and what comes next. Take the placement from the
    `placement` block that `create_task` / `update_task` return — the milestone,
-   step N of M, the next open step — rather than from memory. The
-   `reporting-back` skill holds the shape for each kind of reply: completions,
-   findings, decisions, handoffs, "where are we".
+   step N of M, the next open step — rather than from memory. Scribe delivers
+   the shape for each kind of reply when it is due — the core with each turn,
+   the completion report when a task closes, the asks when you put a question —
+   and `list_reply_shapes` has them all; the `reporting-back` skill holds the
+   reasoning behind them and a completion report worked in full.
 
 ## Stay inside the active project's scope